I jumpstarted my car with a friend the other day, but my car is a BMW so the battery was clearyly labeled with positive and negative ends, so the first time we tried it we did it backwards. Oops. We switched them around, nothing exploded or anything, and we did it the right way, but now my radio unit or my dashboard clock work. Did I blow a fuse that I need to change or are my electronics shot because of the improper jumpstart?