[svx_commuter]

If it's just a piece of metal coming off the CAT or Resonator you may be able to fix it with some wire. Stainless steel wire is best.

What you say does not make a lot of sense to me. The exhaust system runs on the bottom of the car. Above the exhaust pipe, and rear CAT and resonator is a HEAT SHIELD. Above the heat shield is the drive shaft. In all likelyhood it is the heat shield that's hitting the drive shaft. The heat shield is very flexable and can be bent. The drive shaft bearing may also be coming loose. This could be similar to the problem I had. Check out this thread.