My vehicle has a wobble

What is your question?

My 2014 buick enclave has a wobble on the rear end suspension. I have taken it to a GMC Buick service department and the service manager took over the problem. It start with a wobble. They told me to balance the tire. So, I took it to Discount Tire where I had bought two Yokum tires. I had to original tire from the the time I purchased the Enclave. So I had two Michelin in the front and to Yokum in the rear. They rotated them and balance them. I took my car back to the dealer and they said to do a road force test. So took the car back to Discount Tire and they did a road force test. I went back to the dealer with the specs for each tire. The dealer made his own road force test and the max for GMC is 20 and below but he had to modify each tire. I wasn't happy. He said or you can buy some Michelin Tire. So I did and the problem is still there. Do you think it could be the control arm or the lateral control bushings? Need Your HELP. Please

What makes this problem better or worse?

The problem got better when I bought the Michelin Tires but it didn't fix the wobble

How long has your 2014 Buick Enclave had this problem?

4 weeks