Convertible Shake/Vibration
 

I recently traded my 2003 Mini Cooper for a 2005 Mini Cooper Convertible. My trade was made in another state while on a business trip. I of course test drove the car before trading, but not at high speed. From day 1 since driving home the convertible has this really weird shake/vibration that happens between 60 and 75 MPH. What makes it weird is it comes and goes, but mostly comes. I know it is not the tires because I bought brand new ones the day before for my old Mini and had the dealer swap them. Wheels and all. I did not have this problem on the old Mini. I took the convertible to the closest dealer to me and they say nothing is wrong and that this is 'normal' for a convertible. I find it very hard to believe that BMW/MINI would produce a car that has a shake/vibration like this. My windshield mounted GPS looks like jello while on the interstate to the point that I cannot read the directions.

I am hoping that some of you other convertible owners have had similar issues and have a possible solution.

Thanks!!!

Adam