We have a new XC70 with less than 100 miles on it (so far). I know that new cars have breaking in smells (all the new materials get cooked in, etc.) but after each drive, there is a strong burning smell coming from the rear wheels. This is not the tires (I can smell that newness at the front). Is this burning correct? It makes me think something in the rear drive mechanism is cooking rather than free-wheeling. Is it possible come electronic clutch setting is not operating properly, or do the rear drive boots simply heat up and smell until they age a little? <p>(None of the 100 miles has been of the type that would engage the rear wheels).