These newer (1997?? and up) mufflers are stainless coated, and they seem to last forever. I have not replaced a muffler in over 10 years. Also, my son's 2000 trans am has original mufflers after 100,000 miles.
True. As long as the car is driven regularly the exhaust and mufflers will last far longer than they did in the past. Regularly meaning long enough to warm up the exhaust to dry up any condensation. Not so much a problem with stainless steel, but as mentioned before, some parts are not 100% stainless.