I have a 99 ML 320 that is also out of warranty.

1. I paid to repair the my crankshaft dampener pulley. When the campaign came out, I contacted the service manager and they mailed me a check. I had to follow up with them twice, but I eventually got the check. Be politely persistent.

2. Had my truck in last month for something unrelated to the exhaust. Service writer advised me of the cat campaign and said both of mine needed to be replaced (at MBUSA's cost). The cat's are on order right now. The parts guy confirmed to me the list price of those babies is about $1200 each.

3. Remind them that leaking exhaust gasses kill people. It is in their best interest to repair their (design or manufacturing) defect themselves.

Good luck.