[HDGFND]

This is sort of why I like buying older models because a few years into the product being in the hands of consumers, there's a lot of issues that get worked out. Rather have a 2-3 year old model with minimal problems than something brand new with you know what!

 

[HDGFND]

Or could it be an exhaust/tail pipe issue? I don't hear the high pitched hum coming from the engine. I heard it coming from the rear.

That could be it, sometimes issues we experience with cars are simple, in this case maybe just a loose exhaust clamp.