Its been cold and rainy all day today and when I came out from work to start the Bonneville, it sounded like a boat. It almost sounds like theres a hole in the muffler, but closer to the front of the car, seems to be on the drivers side. Assuming this is some type of exhaust leak, will I still be able to drive for a while. In the next two days I have to drive probably almost 200 miles in the B'ville. I have had a chance to visually inspect my wounds, I was just hoping for some pre- feedback. Thanks.

the cat may have been clogged and then blown out.....if there is a hole in the pipe, you may be able to get a exhaust patch to take care of the hole for the trip

The exhaust pipe may have disconnected itself from the catylitic converter.
Does it sound like this?
http://media.putfile.com/100_034753
This was my car when the front flange of the cat broke off and disconnected the exhaust from the motor.
(apologies, but I could only get it in Quicktime)

Check your downpipe and crossover pipe donut gaskets. It appears you may be EGR-less, so you can rule that out.

Could be a cold grumpy car growl. Is it continuing to make this noise all the time or was it just the once?

It made the same noise this morning, although it didnt seem as bad. After the engine warmed up with my head under the hood, I could barely hear it. When im underneath the drivers side I can hear it though.

Yes it sounds very similar to that.

I just checked under the car. The appears to be a small crack right before where the ?downpipe? goes into the cat. Also the support for the cat seems to be just resting under the cat, but it looks like there is a spot for it to mount to. If this is correct then it looks like the mount must have broken off. It is still supporting the cat, but it is not directly mounted to it.

I'd run it by an exhaust shop and have them weld up that crack and resupport it properly. At this point it'll be a cheap fix up.

When I was driving on Thanksgiving the downpipe has completely broken right before the cat. You should hear how loud it is now!!