I purchased my car about 5 weeks ago and I knew it needed tires when I bought it. I put Yokohama parada spec x right after I bought it. I have a vibration anything after 62 mph. I took it back to the tire dealer three times and they ended up force balancing them...still had the vibration. The tire dealer replaced all four today and still have the exact same vibration. He stated that the calabration is set every morning on his machines and that it is not the tires. Ok, we have established that. I took it the dealer and they couldn't figure it out. To add to the this situation, the VDS and the Slip light comes on when it wants to and it stays on until I turn the car off. It would seem that since the warning lights are staying on while I drive, there should be a stored code? I'm trying to figure out what it could be...front differential, transmission, internal engine, harmonic balance? The car is still under warranty and I'm leaving it with them on Tuesday. Any comments?