Welcome to the forum and congrats on your new rig!
I've got lots of opinions on when and why extended warranties might make sense but only as it pertains to motorhomes so I can't help you with the TT question. I would sure think though that if you get a 1 year factory warranty (was it a new unit?) you'd be fine. It's a little different than wanting to protect yourself against having to replace a blown diesel engine...
Feel free to ask any questions you might have. There's a lot of folks hanging out here who know stuff.
Good luck...
Rick