The Trans is 2002 VQ35 LSD. No welding, that's the factory "webbing", Might want to think about having that strengthened next time around. No wheel hop, the mounts are very solid, nice clean burnout, clean launch (minus the spinning). I'd imagine it happened when slamming the gears.
And for the record, Ashton, Yes, I had to drive it home that way, so the edges look rounded from that part of the trans spinning with the axle. It was a little noisy, but the car drove home surprisingly well. There was still quite a bit of gear oil on the driveway the next morning, so I'm not sure what I did to the gearstack by driving it home. All I knew was the car was still able to move and I didn't want to pay for a tow.
Anyway, I guess I'm going to have to open it up, just to see the carnage. Think there's any chance the only damage is to the case (and prolly the diff)?