In texas, ive been pulled over for multiple reasons, usually they come up to the door and say "your not in trouble, im just letting you know" then they proceed to ask if they can check out the truck...
1: Any foward facing aftermarket lights must be covered while on the street(like the kc smiley cover type)
2: Headlights to center 54" or below, Tailights to center 60" or below
3: 2 years ago, they passed the law of : any truck equipped with aftermarket lift must have rear mud flaps/ sling gaurds equipped while on the street
4: Any exhaust modification on a truck must exit no shorter than behind the main cab of the vehicle.
5: any vehicle with aftermarket, lowered headlights to stay compliant must have a DOT stamp on them and the factory headlights if still installed, can not be attached to the headlight switch.
6: Any colored accent lights equipped can not be on while "in-motion" and can only be used while vehicle is in park, unless for use on emergency vehicles or licensed construction vehicles.( construction, wreckers, toll way authorities, ect...)
Thats mainly what ive been pulled over for and have never gotten a warning or ticket.
Ive had one outstanding law enforcement personel pull me over and didnt know the laws, he preceded to ask me if the truck was legal and i had to explain the "state-inspector" definition of everything he asked about.... O_O