Ok well, in response to that, on the forums i agree there are threads that can do with more info, but at the same time the original poster said what he was doing then went silent, so its safe to assume it worked, if it didnt he wouldve been in this thread that night. Anyway;
First up i thought id broken the cv from excess vibrations on a mates driveway (ridges on it like a cow grate), the car didnt make it up the hill before the cv let go. Got it replaced (cv, driveshaft, rubbers etc).
Went about 60m and broke again, the wheel had some huge alignment issues which i assumed was from the work done and was on the way to get al alignment. Towed again, same parts replaced.
Fixed a 3rd time, towed to alignment shop and aligned. Lasted 1km. Towed yet again.
Knew it was something else, towed it to a workshop i use sometimes, sat there for a while talking with the mechanics, we were discussing what could vibrate the joint enough to dislodge something, engine mounts were the logical choice of places to start looking. As ezy9's said, a bar was placed under that point and the motor lifted right up - we all looked at each other and knew what to do.
Nismo mounts fitted (gearbox included), with twin plate at the same time, never had a problem again - after countless launches and generally driving like a tool its still fine.