I wouldn't be too worried. Yes, Amazon may be able to sell the parts for less, but $AAP $AZO $ORLY can still have a competative edge for knowledge and will be able to charge a premium for that. Many aspiring DIY'ers lack the expertise to do it on there own and will need hte guidence from better trained staff. I guarantee that Amazon's customer support chat from India will not be able to lead Americans through a repair.

With the exception of the cell phone, #Amazon has conquered every industry they've gotten into. I see no reason why it can't do that here as it already has tremendous related expertise and everything in place to outsell the existing leaders. $AAP, $AZO, $ORLY may very well follow in the footsteps of ToysRus. I'm very bullish on $AMZN.