There should be an exhaust hanger at the mid point on the car. It would be at the front edge of the first muffler if it had one. I would suggest spending ~$10 on an exhaust hanger and a clamp at a parts store and installing it on the pipe. There are two threaded holes on the chassis where there are probably two pieces of metal meant to accept rubber donut hangers. Remove one to bolt up a rubber hanger (the type that's 6-8" long with a series of holes and a metal hook at one end). Then use the clamp to hold the end with the hook to the pipe. This worked OK on my car.

The problem I had on my car only occured after replacing a clogged cat. It was fine with no center hanger until then, but the new hardware at the 3-bolt flange vibrated loose. The old hardware was so rusted that it had to be cut off, so the vibration was never a factor.
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