I've got a convertible and the rear windows go up and down with some guiding up. Is it normally the motor going out or the guide rod mount? Or is it something I have to check out before I buy?
griding? Sure it is not the plastic pellets in the motor have been chewed up? Does the motor stick? if so, you can replace them with 3 small nuts and they will never wear down. If not, check the bushing guides. They normally wear down and/or break off.