I don't know how you guys are breaking this car. I've owned mine for over a year and the only thing I've done is rounded the crown and input gear in the front diff once. That was because I was stuck on a tube and ran out of patience waiting for a marshal and just pinned it wide open out of frustration
. The car still drove fine, it just chattered while braking.
I think you all need to have owned a B44.x to appreciate the XB4's durability. If you stare at a B44 front arm the wrong way, it breaks. Those POS ball diffs (pick any 4wd car with ball diffs) only last a month of racing under normal conditions before they are roached.