First off - thank you to everyone that replied. It's a great forum and it's awesome to see people try to help out.
Resjudicata - seems we are sporting the same car. I don't like driving 80+ with the top down either. Only so much buffeting the wind deflector can help with. But overall, the top-down wind management is really very good - its my 5th BMW convertible and the best one in that regards. And yes, I have the 20" summer tires on the car (given we have no winter here).
The tires were inspected when the front end was checked. They are fine. Only 2500 miles on them and the car. But interesting point is that I took a drive to Flagstaff in Northern AZ and the car was very planted on the mountain road. But every once and a while I'd get turbulence off a truck or a gust from a mountain pass and it would push the car around in the lane. I found that if I went faster, it would hunker down more and the stability got better. Guess that means I have to drive 100+
