He can't take you to jail simply for a minor traffic ticket. And by this I mean yes, he could -- but police departments have policies against that sort of bull and he'd get in trouble for it and he knows it.

Personally, if anybody asks to search my stuff, I'm going to answer no, even though I won't have anything to concern them. He can't officially punish you for not giving him permission, and while he could unofficially punish you ... they usually know better. And if he doesn't need permission, he'll search with or without it. That said, I do understand how it's just easier to agree ...