As in any modern luxury car, the parts most prone to failure are the 'luxury' features like powered accessories, air suspension and electric systems. Tesla has plenty of those, if not more than a comparable competitive products like let's say a Mercedes S class or Audi A8. Even though the latter have also engines and transmissions that can fail they usually don't and it's fairly rare to have those replaced or repaired (at least in the first 5-10 years/100k miles as these cars are usually not owned for longer than that by their original owners).