I don't want to buy a priority battery from Jaguar. What other car model battery would work in a 2002 X-Type Jaguar.

Maybe a Motorcraft (Ford) will work fine, (I bought one) but be carefull to make a "back-up", never disconnect the battery at 100%, it make troubles with the computers modules, and will send error codes, someones do this "back-up" with another battery (befores disconnecting it) or a kind of plug-in battery to the cigarrette lighter, then, when you change the battery, start the car and lights (high), A/C, radio etc., then turn off al, then l and the car, even remove key, wait a minute, and start the car, if an error message appears, do the same again, if still, you´ll need to get an scanner reset. Get Luck!