I've got a set of Bridgestone Potenzas on my stock-wheels 2002 scooby; only 10k on them so far, but I get a marked vibration at 75-80 MPH (it goes away past 80). Since the vibration is in such a narrow band, that seems to rule out brake rotors or wheel balancing, right? Has anyone else had wheel vibration at that speed with stock wheels/tires?

On a related note, I may go to 17" rims and new rubber soon -- anyone reccomend some grippy tires for HOT, FLAT, DRY roads?

 

Get your Wheels and Tires rebalanced and you should be all right. That is more than likely what your problem is.

 

Also, if the problem persists - find a place with a Hunter 9700 GSP machine. (http://128.242.141.111/pub/search/findgsp9700.cfm) It has a "road force variation" measurement that finds the high/low spots on your wheel and tire to give a more perfect ride.