Originally Posted by Roen
They can, actually. All they need is a suspicion and then they can pull an excuse to search out of their arse ad hoc. So, even if the gear were in the trunk, there would still be a possibility of a search anyway. "I thought I smelled an illicit substance... " then bingo, full search. It's amazing how many drug busts they make this way.
But if they don't find anything related to any illicit substances, I believe you can have any non-drug related evidence thrown out in court, because if the cop says he smelt drugs, and there weren't any drugs, he's obviously fucking retarded.