Thanks for the reply Chips229. What is a tracking check? If this is the same as an alignment you just might be on target.
Today (Saturday) the dealer swapped the tires by removing them from the rims and moving them left to right but the pull to the right persists.
However, today they found an alignment problem caused by a rear strut :( . Because the strut is not adjustable they will need to order a new one and it won't be delivered until Tuesday at the earliest.
I asked how a new car could be out of alignment and they had no idea. I know that in the few miles that I drove the car nothing occurred that could have caused such a problem. Maybe it happened when being transferred off the boat? I do know that there was no perceptible alignment problem symptoms prior to installing the Michelins. The car tracked perfectly until the Michelins were installed.
Upon researching the review narratives for the tire on Tirerack.com a few people reported having a unsolvable problem of the Michelin Pilot Sport A/S pulling to the right. But there are also several reviewers with heavier cars similar to the 430LS that have not had any problems.
I also discovered that Mercedes has issued a service bulletin stating that they will not do alignments on Mercedes that have this tire.
I will post an update when something new developes. In the meanwhile if anyone has any ideas I sure would appreciate hearing from you.