Bought it new a couple weeks ago, it seems to have a weird roar or hum in the rear end at about 70mph, is that normal. Can't pin point what it might be.

 

Have someone else verify, maybe even record it.

 

Depending on your location it take a little time for the rear diff. to get to temp which can cause a hum or vibration-- this stops after a few miles

In cold temps tire can develop flat spots from sitting in the cold conditions over night-- this also stops after tire temps rise.

It also could be a balance issue. does its sound different at high speeds then slower?
If this isn't the problem then I would check your lugs


More info would help your cause. When does it happen and how long??

 

I haven't noticed it in mine. I'll listen next time I drive it. How many miles does it have?

 

just turned 1100 miles, nothing is shaking it rides very smooth, not like a tire balance issue. Sounds like it coming from the rear end. I'll try and go by the dealer but, i'm sure they will say its normal. But, it's not