I have a slight front end vibration that I can't seem to get rid of, I had this problem since I changed out the 16 inch stock wheels to stock 18 inch RX-8 wheels. When I put on the RX-8 wheels the tires had about 50% life left so I figured I would get the wheels and tires balanced and that would solve my problem but it didn't so I then had the wheels and tires rebalanced, front end alignment(which the shop said they had trouble with because I changed wheels and tires and its no longer could be done to Mazda 3 specs) and the rims checked to make sure I didn't have a bent rim but everything turned out to be fine. Once the tires got to the point where they needed to be replaced I got a new set and still have the front end vibration, I took the car to Mazda and had them check the front end and everything was in good condition, The service tech said that I could be having this issue because the stock RX-8 wheels are for a RWD car and I have a FWD car. What are your thoughts about my situation? If the problem is because of the wheels i'll live with it