Originally posted by JayBee
If it's not too much trouble, can SOMEONE answer my thread? 
Give us some more specifics, like what model speed control you were using. If you had your car over geared, that combined with the fact that you were using a motor that was right at the limit of your ESC may have been enough to fry it. Was your motor really hot at the end of each run to the point that you couldn't hold your finger on it for more than a second or two? That's a sure sign that you were over geared.
On the other hand, it could just be a bad/cheap ESC.