Good luck, sound like you're on the right track. True, once the ticket was written, even if proper, the cop has to let you on your way without probable cause that a crime has been committed or reasonable suspicion that warrants further investigation. And there can be personal liability for the cop for a civil rights violation, though the agency covers any liability.

You should be careful when it comes to trying the case, that's not easy. At least bone up on evidence law. And too, you might win and obtain only a small judgement given that you did not go to jail for any real period of time. You hear about verdicts of $1 sometimes. The federal civil rights laws provide for attorney's fees to be paid if you win even a dollar. Having gone this far, you might want to discuss with a lawyer to take the case the rest of the way. Their fees will get paid and the presence of a lawyer and the potential for the fees may force a settlement. Good luck again.