I test drove a 2000 s2k today with 38k miles on it. I heard a whinning noise like something is rubbing in the rear of the car. It only happens when i let off the gas pedal and cruise with it still in gear. Is this normal or is there something wrong with the diff or tranny.

 

This car normally makes all kinds of gear noises when driving. Without actually hearing the sound, who can say if you've got a problem.

 

If you are thinking about buying the car and are in doubt of the sellers word, don't be afraid to have it looked at buy someone. I have a 01 that makes gear noise, I have talked to several other people with the earlyer generations and they say the same. I would agree with xviper, without hearing it who knows for sure.