I was having the same problem as well a little while back. Put on new wheels and tires and had the alignment checked and still had a shimmy between 60-70. took it back again and had the wheels rebalanced again ( they were off} and that basically got rid of it. I say basicaly because there is still a very very slight shimmy, but I can live with it. Toyota wheels are a ***** to balance. The guy a the toyota dealership even told me that they have problems doing them and that they end up sending them over to their ford dealership to have done on a Road Force machine which I guess is pretty high tech. It applies force to the tire while balancing and can actually center the tire itself on the wheel. Price starts and $50 and can get up to $80 depending on what all they have to do. Do what I did and just tell the garage that installed your tires, that if they cant get them balance your taking it elsehwere and giving them the bill! They'll get those suckers balanced!!