Checked the heat shield
Having noticed that a bit of the heat shield was loose, when I last washed the A2, today I put the car on the ramp to assess the situation:
The loose shield was due to the fastener being completely corroded (they look like steel to me) and I guess then having contact corrosion with the aluminium shield. Looks like a new small shield. I hope the big shield is OK.
I then looked at the other fasteners. Here's a general view of under an A2 (not mine!) with the rivets marked:
The fasteners attached to the fuel tank (circled red) were very corroded. I guess Audi thought they could use steel as the tank is non metal.
The ones attached to the floor pan (orange) were fairly corroded.
The next least corroded were the one attached to the battery box (green):
Not corroded were the ones along the "transmission" tunnel (blue).
I couldn't release the fastener on the broken heat shield, despite some WD40, so as a temporary and very crude fix I screwed on a bit of an old angle bracket:
So, looks like a new small heat shield (anyone know the £ damage?). In this recent thread
http://www.a2oc.net/forum/showthread.php?30198-Rivnuts&highlight=heat+shield Matt is going for aluminium rivnut size M6 but he doesn't say what length. If you're reading this Matt perhaps you can say what length you used.