My car is really noisy when you put it in reverse... makes a sort of a "humming" noise. Not sure if this is normal or not. Does anyone else'* car do this?

The way the reverse gear is designed, you'll often get a hum from the car when moving in reverse more than a few MPH. If you've ever owned a manual transmission it'* much more apparent. Now I don't really have a reference as to how loud it really should be though, that I do no know. If your car is making the noise while stationary, then its beyond my limited knowledge.