I'm looking at a 99 Cobra and the speedometer is inaccurate. The car didn't feel like it had a rear gear swap. I was wondering what might cause this? Also, if I change the instrument cluster is the odometer reading recorded in the instrument cluster or some kind of brain box? I would like to switch to an 03/04 cobra cluster will this change the odometer reading? Any info please. Sorry I've never owned a sn95 car so its all new to me.