2nd qualifier of last night's club race... snapo!
Average crash, buggy landed hard on left rear wheel after double jump attempt (nothing huge). Another 501X owner at our track broke the same piece at a regional race a couple months back and from what I hear was replaced with a stronger piece (apparently Tamiya knows about this problem and his new piece looks identical, so hopefully a stronger type of aluminum, maybe forged and not cast).
Rear shot ...
http://img67.imageshack.us/my.php?image=img0598as9.jpg