When I changed the exhaust on my MK4 3dr the rear silencer heatshield was corroded through at the bolt points. The bolts themselves were also solid to the extend that one sheared off when we tried to loosen it.

We got that one fixed back on, kind of by cheating (don't like this!) with self-tappers. Now the centre heat shield is loose and is knocking on the centre silencer - not all bolts have gone the same as the rear shield, but the loose one certainly has - I seriously doubt the bolt would come off without breaking it again. The OEM exhaust was large enough to keep the shield in place without the need for these bolts, but the SS catback system I now have has loads of room around the silencers and is not close to being able to keep them in place.

Is there any easy fix to putting the shield back on without resorting to welding a new bolt?