Just had my car at the dealer. They do not charge for a diagnostic if they don't find anything wrong.
AAA offers a warranty that they sell. It is not AAA branded just a company they use.
The prior owner has filed claimes with them and there were no problems. They approve the repair over the phone and give the dealer a credit card #.
The original price for the warranty was 1295.00 Platnum, which is full coverage.
Best,
Jordan