[fullthrottle52]

Well, just as I suspected. I have one front rim tha is out of round. A very experienced tire guy where I bought the tires put both front rims and tires on a balancer. Spun it and by holding an ice pic very steady could tell that one of the rims has a slight low spot on it. It left a mark about 6 to 8 inches long on the inside of the rim. He said it is enough to cause a shake at higher speeds. The other one has a very slight high spot but not nearly as bad as the other one. It still does not answer the shaking issue I was getting at 40 mph first thing in the morning but that seems to have gone away with the Michelins. Now only slight shake at 50 to 60 mph and then gets progessively worse as you go up. After rebalancing again today after finding the flat spots it is slightly better but still very uncomfortable to drive at 70 to 75 mph.

I guess I am now looking for an 18 in OEM Boxster wheel. I have to look at the inner rim to see if they are 7.5 in or 8 in. rims and then start my search. If anyone here has one for sale or knows a good source, let me know.

thanks again for all the input. I hope I can get this resolved soon. I may just have to wait until Spring now, but at least i know it is not tires and can wait.