When a loan is cosigned, the lender can and will go after whoever has the money to make the payments. That's what cosigning is all about.I'm guessing that right now, if the OP is making payments, the lender won't go after anyone. Maybe if the OP stops payment, but then his own credit rating would suffer, which can affect car insurance rates even if he has no plans to borrow money.
No only will the OP's credit rating suffer, they could get sued for the unpaid money, along with legal fees.