So I had aftermarket wheels on the truck (305 50R20) and then recently put on the Saleens. WELL 2 days after the install I noticed a squeak coming from the rear end. It's a light (but still very detectable squeak) one that I cant trace to one side or the other. It WILL drive me nuts though as the frequency is high enough to get through my tunes driving around (I keep it mellow) and now that I am listening for it

They road force balanced the rims, but it was 45 mins before they closed (Les Schwab) and were in a rush so I dont know if they were 100% on it.

There is NO shudder when braking
The squeak is NOT really speed dependent.
It has NO change with bumps in road.
NO change with turning
CANT replicate by shaking the hell out of the bed when parked.
Brakes have 600 miles on them with no sounds, and are in perfect order.
WILL drive me Banana Sandwich.

Any ideas?