Probably should mention, in light of the Haddad case that I discussed in my previous post, that you should NEVER consent to a search by a police officer.
They have no legal right to search your belongings during a routine traffic stop.
The only thing they are allowed to do is frisk you for weapons under the guise of officer safety. Without probably cause they can't root through your stuff unless you let them. Don't let them. Don't let them intimidate you with the argument that if you have nothing to hide you should consent to a search. The courts have ruled repeatedly that failure to consent to a search is NOT probably cause to conduct a search.
If you get pulled over and asked to get out of the car, consider locking the car and putting the keys in your pocket after you get out.
Nathan Haddad consented because he didn't think he was breaking any laws and now he is facing up to 35 years in prison and the almost certain loss of his right to own firearms.