Regarding ur wheel balance issues. I have had 4 E63’ over the years. Currently have a 2018 bought new. 54,000 miles. 4th set of tires. All have been Michelin PS4. Super meticulous about it and very specific about high speed vibrations. I have one specific tire dealer I’ve been using for over 30 years. Live in a suburb of Chicago. I have immersed myself in how they are balanced and the reason causing different vibrations. Always have the luxury of having one tech who balances my tires. There’s a certain tolerance that Mercedes dealers use when that road force there wheels and tires. They said it’s within THERE specs because they don’t want to spend the time to keep turning the tires on the wheels to get them down to as low as possible.Too technical to go into but on the road force machine as long as the machine gets the number down below 15-16 Mercedes says that within the specs of tires being balanced. I’ve found many times that IF a rim is slightly bent or a tiny bit out of round that will throw the whole car out of balance and cause high speed vibration. One time a tire was deformed and had to replace it. On a occasion or two all rims were fine and as the tires were balanced the number on the road force was too high in my opinion but within factory recommendations. I asked my tire tech to keep breaking the tire down on rim and turning tire on rim and rebalancing until I got those numbers down below 11 and sometimes as low as 5. Very time consuming but once they were done over and over the car at over 100 and up was perfect. I have watched him over many years and I can tell in a minute or two how that tire/ wheel will be. Perfect or not? As I said NO dealer will spend the time and neither will most tire chains. Bottom line all those suspension problems might cause high speed vibration but my hunch is on poor wheel balance / bent rim. PS. OBVIOUSLY need to use latest Hunter/ Road Force machines.

 

MANY years ago...(I am old) the best place to buy tires (up there) was Tire Rack (in Indiana) at the South Bend facility. Man. we had some good events there over the years.

Even longer ago...day trip from South Bend to Barrington to go to the theater and watch the opening night of The Fast and the Ferious. Every car club was there....every theater I think played the movie at the same time. Barrington police actually let us street race at the Ameritrech building.....(yes, I am old). At that time I was in a 3000GT VR4 (3 of em).

 

I had a 92 VR4...I really enjoyed that car. I sold it because I couldn't stop myself from constantly modding something.

First time I ran into vibration issues was with that car both times I bought new wheel/tire sets. Les Schwab, a regional tire deler, never got it right. I had to take the car to an old school tire shop to get a proper balancing.