Thoase of you with dealer lowered and / or 18'' wheel upgrade, do you know if your dealer performed a 4 wheel alignment after the upgrade?
It seem that an alignment is recommended after the upgrade.....

 

I have the TRD 18" wheels on mine, and I didn't have an alignment done. I actually picked up the rims from the dealer and installed them myself. I think it would be necessary if you lower it, but not just swapping rims/tires.