Find someone who can "Road Force" balance them!! This procedure puts pressure on the tire while balancing as if the weight of the car is on it and defines "Hard Spots" in the tire as heavy spots.
If done properly the car will be very smooth but as stated before a "Bump Steer" type of shake will always be apparent in light weight cars with wide tires and rack & pinion steering!!
Good Luck!!
Coosawjack
