Replaced the muffler system on the 240 wagon just 2 years ago. the car has been garaged both winters. both the center pipe and tail pipe look closed to brand new.
On the other hand, the pipe that is integral to and exits the center muffler has broken away. This is from metal fatigue, not rust. Also the bracket that is attached to the tail pipe end of the rear muffler has now broken away for the same reason and is leaking from the resulting hole. I doubt I have 15,000 miles on this Wagner system.
Luckily I saved the the Bosal system from my expired 89 240 that had seen 2 winters and still looks in great shape.