My car - 2001 Mazda 626 has a hump in the middle back seat area. Right now my daughter is in a graco snugride and it is installed in the middle. I've noticed lately that the seat is beginning to lean more towards one side (I think that's from the sealt belt though, we need to go uninstall and reinstall with the seatbelt clip.) I was just wondering if that hump in the back seat will be a problem for a convertible car seat. I would assume that middle back seat is best, but is it ok to install the seat on one of the sides?