Can a car be reposessed with out notice even if you have a cosigner?

If you believe neither of you have received notice, then request proof from the lender. This doen't mean that just because neither of you signed for the notice that you can say it wasn't received. If they can show that it was mailed and returned...it was enough. They tried.

Have you talked with the cosigner, because this will be on both of your credit reports. If they don't have any proof.. get an attorney.

Good luck