get your wheels balanced...a HIGH SPEED balancing..and an alignment. should take car of the problem for sure..
This will do the trick. It is actaully called "road force" balancing. Not every shop does this because teh machine is expensive. In my city of a million people there are only two shops.
"Balancing your tires is the key to you and your vehicles well-being and comfort. It is done to ensure that your tire & rim assembly weighs exactly the same around the contact area of the tire to eliminate vibrations. Road force balancing and then force matching the assembly is the next step. This ensures that that tire and rim (when mounted together) are as "round" as possible. Tires and rims both have high and low spots, If these high spots are in the same place on the assembly they can cause a vibration even if the assembly is perfectly balanced. What we can do to eliminate this problem is measure the "Radial Runout" (up and down) and "lateral runout" (side to side) on both the tire and the rim and match them so that the high spot on the tire lines up with the low spot on the rim."