I have yet to see them on a GP on the road. But as long as you like'em... who cares!! Congrats
Don't your pontiac caps fit?

You will notice that your tires like to ride in the grooves of the road. EX. If you drive by a quarry that has alot of full dump trucks on it, your car will pull into the groove/low spot on the road. At least mine do, but I think it has alot to do with the tire compound... and mine are hard. Kuhmo Ecsta SPT 245/45/17