I just picked up a 06 copper ( R50 ) it's my 1st one. I found out the speedodmeter is reading 5 mph faster then the car is really going. what can I do to correct this problem ?? can I put a larger set of tires on the front and leave the smaller tires on the back or would that effect the abs and dsc systems ?? can I change the speed sensor or does the speedodmeter run off the same system as the abs ?????????????? thanks