This one isn’t mine. The key is to find a very good diagnostician for when problems do arise. Mine is a 20+ year Jaguar mechanic based in the MD/DC/VA area. I think it’s fair to say that I spend half taking XJ6 cars to 200K than most folks do taking Ford Tauruses to 200K. And while most folks try to buy the “latest features,” my next daily driver will probably be a 70s or 80s XJ. They’re that great, and we only live once.
Older Jags don’t command very high prices and if the engines gives much trouble kits are available to put older GM engines in them without torch work.
The purist may bulk at the idea but it does work.