If it IS a balancing problem, you have tro find the tech who knows what he's doing...
Larry, believe it or not, I think my woes with vibration on my CLk55 and 19" SSRs are finally over. And guess what fixed it...a Coats. I had been to 2 shops, both with GSP9700s, back and forth to both at least 3 times. I had almost given up and was getting ready to E-Bay the wheels and a wrench friend who is really a Porche specialist asked to take a shot at it. 2 wheels had too much weight on them. All of them were off by about .2 oz and placement was off by a few mm. He said what happens is when they put weights on 1 side then spin it again, if the computer says too much weight was put on, instead of taking it off and putting on less, they would just compensate with weights on the other side, and so on, and on...1 wheel actually had a total of about 3.5 oz. and after he was done, he had only 1.25 oz. total. I took it for a spin on a parkway at 65-75MPH and it felt smoother than at any other time with these wheels. I have to cruise with it to really make a fair judgement, then I'm posting a "closure" to my ordeal. My friend's Coats didn't even have provision for 19"s. The dial only went to 17 or 18. But again, the most important thing is still the person behind the machine. I still think the Hunter is an amazing machine but only with the right tech using it; otherwise, it's a very expensive piece of junk.