The following are excerpts from the California Vehicular Code as they relate to 4x4 trucks:
Vehicle Bumper Requirements
28071.Every passenger vehicle registered in this state shall be equipped with a front bumper and with a rear bumper. As used in this section, "bumper" means any device designed and intended by a manufacturer to prevent the front or rear of the body of the vehicle from coming into contact with any other motor vehicle. This section shall not apply to any passenger vehicle that is required to be equipped with an energy absorption system pursuant to either state or federal law, or to any passenger vehicle which was not equipped with a front or rear bumper, or both, at the time that it was first sold and registered under the laws of this or any other state or foreign jurisdiction.
35408.In no event shall a front bumper on a motor vehicle be constructed or installed so as to project more than two feet forward of the foremost part of either the fenders or cab structure or radiator, whichever extends farthest toward the front of such vehicle.
Brake Requirements
26450.Every motor vehicle shall be equipped with a service brake system and every motor vehicle, other than a motorcycle, shall be equipped with a parking brake system. Both the service brake and parking brake shall be separately applied.
If the two systems are connected in any way, they shall be so constructed that failure of any one part, except failure in the drums, brakeshoes, or other mechanical parts of the wheel brake assemblies, shall not leave the motor vehicle without operative brakes.
Headlights and Off-Road Lights
24400.(a) A motor vehicle, other than a motorcycle, shall be:
(1) Equipped with at least two headlamps, with at least one on each side of the front of the vehicle, and, except as to vehicles registered prior to January 1, 1930, they shall be located directly above or in advance of the front axle of the vehicle. The headlamps and every light source in any headlamp unit shall be located at a height of not more than 54 inches nor less than 22 inches.
(2) Operated during darkness, or inclement weather, or both, with at least two lighted headlamps that comply with paragraph (1).
(b) As used in paragraph (2) of subdivision (a), “inclement weather” is a weather condition that is either of the following:
(1) A condition that prevents a driver of a motor vehicle from clearly discerning a person or another motor vehicle on the highway from a distance of 1,000 feet.
(2) A condition requiring the windshield wipers to be in continuous use due to rain, mist, snow, fog, or other precipitation or atmospheric moisture.
24402. (a) Any motor vehicle may be equipped with not to exceed two auxiliary driving lamps mounted on the front at a height of not less than 16 inches nor more than 42 inches. Driving lamps are lamps designed for supplementing the upper beam from headlamps and may not be lighted with the lower beam.
(b) Any motor vehicle may be equipped with not to exceed two auxiliary passing lamps mounted on the front at a height of not less than 24 inches nor more than 42 inches. Passing lamps are lamps designed for supplementing the lower beam from headlamps and may also be lighted with the upper beam.
Auxiliary Lamps: Off-Highway Use
24411.Notwithstanding any other provision of law, a vehicle may be equipped with not more than eight lamps for use as headlamps while the vehicle is operated or driven off the highway. The lamps shall be mounted at a height of not less than 16 inches from the ground, or more than 12 inches above the top of the passenger compartment, at any place between the front of the vehicle and a line lying on a point 40 inches to the rear of the seat occupied by the driver, shall be wired independently of all other lighting circuits, and, whenever the vehicle is operated or driven upon a highway, shall be covered or hooded with an opaque hood or cover, and turned off.
Foglamps
24403. (a) A motor vehicle may be equipped with not more than two foglamps that may be used with, but may not be used in substitution of, headlamps.
(b) On a motor vehicle other than a motorcycle, the foglamps authorized under this section shall be mounted on the front at a height of not less than 12 inches nor more than 30 inches and aimed so that when the vehicle is not loaded none of the high-intensity portion of the light to the left of the center of the vehicle projects higher than a level of four inches below the level of the center of the lamp from which it comes, for a distance of 25 feet in front of the vehicle.
Spotlamps
24404.(a) A motor vehicle may be equipped with not to exceed two white spotlamps, which shall not be used in substitution of headlamps.
(b) No spotlamp shall be equipped with any lamp source exceeding 32 standard candlepower or 30 watts nor project any glaring light into the eyes of an approaching driver.
(c) Every spotlamp shall be so directed when in use:
That no portion of the main substantially parallel beam of light will strike the roadway to the left of the prolongation of the left side line of the vehicle.
That the top of the beam will not strike the roadway at a distance in excess of 300 feet from the vehicle.
(d) This section does not apply to spotlamps on authorized emergency vehicles.
(e) No spotlamp when in use shall be directed so as to illuminate any other moving vehicle.
License Plate Lamp
24601.Either the taillamp or a separate lamp shall be so constructed and placed as to illuminate with a white light the rear license plate during darkness and render it clearly legible from a distance of 50 feet to the rear. When the rear license plate is illuminated by a lamp other than a required taillamp, the two lamps shall be turned on or off only by the same control switch at all times.
Fenders and Mudguards
27600.No person shall operate any motor vehicle having three or more wheels, any trailer, or semitrailer unless equipped with fenders, covers, or devices, including flaps or splash aprons, or unless the body of the vehicle or attachments thereto afford adequate protection to effectively minimize the spray or splash of water or mud to the rear of the vehicle and all such equipment or such body or attachments thereto shall be at least as wide as the tire tread. This section does not apply to those vehicles exempt from registration, trailers and semitrailers having an unladen weight of under 1,500 pounds, or any vehicles manufactured and first registered prior to January 1, 1971, having an unladen weight of under 1,500 pounds.
Mirrors
26709.(a) Every motor vehicle registered in a foreign jurisdiction and every motorcycle subject to registration in this state shall be equipped with a mirror so located as to reflect to the driver a view of the highway for a distance of at least 200 feet to the rear of such vehicle.
Every motor vehicle subject to registration in this state, except a motorcycle, shall be equipped with not less than two such mirrors, including one affixed to the left-hand side.
Frame and Floor Height
24008.5.(a) No person shall operate any motor vehicle with a frame height or body floor height greater than specified in subdivisions (b) and (c).
(b) The maximum frame height is as follows:
[This table lists the maximum frame height for various types of vehicles.] *Vehicle Type / Frame Height
(1) Passenger vehicles, except housecars / 23 inches
(2) All other motor vehicles, including housecars, as follows:
Up to 4,500 pounds GVWR / 27 inches
4,501 to 7,500 pounds GVWR / 30 inches
7,501 to 10,000 pounds GVWR / 31 inches
(c) The lowest portion of the body floor shall not be more than five inches above the top of the frame.
(d) The following definitions govern the construction of this section:
(1) "Frame" means the main longitudinal structural members of the chassis of the vehicle or, for vehicles with unitized body construction, the lowest main longitudinal structural members of the body of the vehicle.
(2) "Frame height" means the vertical distance between the ground and the lowest point on the frame, measured when the vehicle is unladen on a level surface at the lowest point on the frame midway between the front axle and the second axle on the vehicle.
(3) "GVWR" means the manufacturer's gross vehicle weight rating, as defined in Section 390, whether or not the vehicle is modified by use of parts not originally installed by the manufacturer.
Exhaust
27152.The exhaust gases from a motor vehicle shall not be directed to the side of the vehicle between 2 feet and 11 feet above the ground.
Mirrors
26709.(a) Every motor vehicle registered in a foreign jurisdiction and every motorcycle subject to registration in this state shall be equipped with a mirror so located as to reflect to the driver a view of the highway for a distance of at least 200 feet to the rear of such vehicle.
Every motor vehicle subject to registration in this state, except a motorcycle, shall be equipped with not less than two such mirrors, including one affixed to the left-hand side.
(b) The following described types of motor vehicles, of a type subject to registration, shall be equipped with mirrors on both the left-and right-hand sides of the vehicle so located as to reflect to the driver a view of the highway through each mirror for a distance of at least 200 feet to the rear of such vehicle:
(1) A motor vehicle so constructed or loaded as to obstruct the driver's view to the rear.
(2) A motor vehicle towing a vehicle and the towed vehicle or load thereon obstructs the driver's view to the rear.
(3) A bus or trolley coach.
(c) The provisions of subdivision (b) shall not apply to a passenger vehicle when the load obstructing the driver's view consists of passengers.
Exhaust Pipes
27152.The exhaust gases from a motor vehicle shall not be directed to the side of the vehicle between 2 feet and 11 feet above the ground.
27204.For the purposes of Section 27200, the following noise limits shall apply to any motor vehicle within the specified manufacturer's gross vehicle weight rating and date of manufacture:
[Noise limits for vehicles with a gross vehicle weight in excess of 5,999 pounds.] *GVWR-Pounds / Date of Manufacture / Noise Limit -dbA
Over 6,000 / after 1967 and before 1973 / 88
Over 6,000 / after 1972 and before 1975 / 86
Over 6,000 / after 1974 and before 1978 / 83
Over 8,500 / after 1977 and before 1982 / 83
Over 6,000 but not over 8,500 / after 1977 / 80
Over 8,500 but not over 10,000 / after 1981 / 80
Over 10,000 / after 1981 and before 1988 / 83
Over 10,000 / after 1987 / 80
Yes, theres Rules on Caravans!
21705.Motor vehicles being driven outside of a business or residence district in a caravan or motorcade, whether or not towing other vehicles, shall be so operated as to allow sufficient space and in no event less than 100 feet between each vehicle or combination of vehicles so as to enable any other vehicle to overtake or pass.
Miscellaneous
21710.The driver of a motor vehicle when traveling on down grade upon any highway shall not coast with the gears of such vehicle in neutral.
25100.(a) Except as provided in subdivisions (b) and (d), every vehicle 80 inches or more in overall width shall be equipped during darkness as follows:
The rest of this has been intentionally ommitted due to length, if this applies to you look up the code at dmv.ca.gov.