Last month I traded my KZ Jag in after it was 8 years old, but not because it had reached the end of its useful life. Conversely the TT was in beautiful condition because I kept it that way. I traded it because I wanted something bigger with more convenience options. It had well over 100 nights spend in it, but still looked brand new. And I even upgraded certain parts of it. If maintained, someone should enjoy that TT for another 10 years.
Unlike my daughter's car that we just traded in, which was starting to cost more and more money in repairs (water pump, suspension, cooling system, tires, etc). The car was 10 years old and had 135K miles on it. Nonetheless, someone should be able to get another few years out of it, albeit with some money needed for ongoing repairs.