I velcroed for a while, but have gone back to body clips on the B44.
Basically, clips will not let you down after a rough incident or aggressive marshalling. It's a bummer to have a shell flapping around or (worse) jammed in a weird position fouling mechanisms because it gets partially pulled up on one one side. At least with clips you know that the shell will snap back to where it's supposed to be.
The B44's undertray is a bit wobbly at the best of times even when brand new, and by attaching the shell to the undertray, you're basically just holding the shell on by those three mounting screws on the underside of the chassis and (possibly) those little "sails" on the chassis' edge. A bit ropey in my experience....
Saying that, I still use velcro on the gold pan RC10, as the chassis has such rigid "walls" that its' a pretty solid connection. That and I've used velcro on that particular car for well over 20 years with no hassles...
