Phaeton vibration in seat and steering wheel

Hello dear Phaeton friends. I have a little problem with my fat one. I drive a 3.0 Tdi built in 2013. I bought the car in October 2015 from a VW dealer with a mileage of 59000Km. As it was going towards winter I had the winter tires pulled up which I got nail new from VW. After a certain time I noticed that the car vibrates from ca 80kmh to ca 110kmh. The whole thing can be noticed by a citing in the seat and on the hand if you put it on the selector lever for example. I then drove to my workshop to which my cars go when they are out of the warranty because I have always had bad experiences with the VW workshops. The master made a test drive and also he noticed the problem. He then took the car on the stage and let the wheels run free. With a close look you saw the wheel slightly up and down the left. So off to VW because he during the guarantee there did not want to. According to VW the rim was cleaned out and everything was fine. Now the question arises to me why the at that time not balanced would when the new tires came up but good. The problem was not really gone but I waited until the summer to try it with the summer rims. Spring came up mature summer and the problem was still there. Since the tires were not the best I had new ones raised and even measured the axle of VW l assen. Now the problem is still there and today I noticed that when I push the whole car against the fender the whole car is shaking and swimming. In addition, the steering wheel is shaking during the ride. I soon wanted to have an appointment with VW again but asked if someone can help me here so that I can give me some reasons. Thanks already and a nice Sunday still.