Never Let the Police Search Your Vehicle
Everybody repeat after me, "I will never, ever give a police officer permission to search my vehicle. If he wants to search it he can come back with a fucking warrant." Even if you have nothing to hide the police will plant evidence in your vehicle if they want to nail you. Don't believe me? Why don't we ask Officer Bill Glass:
A former Haskell police officer was found guilty after pleading no contest to fabrication of physical evidence charges.
Bill Glass resigned from the Haskell Police Department in March of 2010, saying allegations he'd planted methamphetamine in a car during a traffic stop were "baseless." When the drugs were sent off for testing, a chemist at the lab traced them back to the officer.
When you give an officer permission to search your vehicle your are giving them an ample opportunity to boost their arrest numbers by fabricating evidence. Unless the officer has a warrant or probably cause (which basically means any poor excuse an officer can fabricate, but at least it's something) they can not search your property without express permission.
If you're asked to step out of your vehicle during a traffic stop do so but make sure you lock your car doors and put your keys into your pocket before exiting the vehicle. At any point during the traffic stop if an officer asks, "May I have a look inside the vehicle?" you should only responsd by saying, "No." Ignore anything they say after that because they're going to try guilting or threatening you into giving them permission. Do not say anything further because the officer will try to hang you with it. In fact it would be a very good idea to get your lawyer on the horn at that point in time.