If there are 2 people in the car and your friend has it or puts it under the seat 1 of 2 things could happen providing the cop doesn't take it for personal use:
A. your friend gets in trouble ( if he owns up to it )
B. you get in trouble because it is your car.
It all depends on the cop. I have seen it go both ways on COPS.

DO NOT EVER GIVE CONSENT TO SEARCH YOUR VEHICLE WHATEVER YOU DO!!!!!!!!!!



A LITTLE ROLE PLAYING HUH?

YOU: speeding down the road Shit the fuzz is pullin us over man
(now is the perfect time to get stories straight so if you manage to get seperated, the stories match!)

COP: Approaches window of car "Registration, insurance, blah blah blah"
YOU: Give it to him and be polite and calm holdin that zone under your seat
COP: Where are you going ?
YOU: That is really none of your concern (politely) I am kind of pressed for time, If I could have my ticket and be on my way that would be helpful to me.
COP: DO you have anything illegal in the car?
YOU: NO
COP: Do you mind if I look around?
YOU: Yes I do, as I said before I am kind of pressed for time and would like to be on my way.
COP: Can I search your car?
YOU: No you may not unless I am under arrest or you have a warrent to do so.
THAT WILL SHUT THEM UP. Once they know that you know your rights they usually just write tha ticket and let you go. If they search anyway It is now illegal and you may request a supervisor be present while that search is conducted ( THAT IS YOUR RIGHT ). If that right is denied the case will be thrown out most likely. HAPPENED TO ME. DISMISSED ON GROUNDS OF ILLEGAL SEARCH AND SEIZURE. sorry so long