Question for those with the R/T. We got a set of 20" last week. I noticed the same low speed vibration as another poster. Also, at speed, say 50mph and over, we notice a loose on-center feel in the steering wheel. In simple terms, it wanders a bit. Takes a lot more effort to keep straight. Anybody else with this issue? Any suggestions? Shop said they can order a cam kit and do an alignment to try and correct but that shouldn't be needed with no lift. Any help is appreciated. We have the 500 mile guarantee, so perhaps switching to AT2 is a better solution?