The early V8 ( pre 01) cars have expen$$$ive engine issues. Timing chain tensioners fail, causing chains to break. Big bucks to fix after the fact, 1600.00 or so to replace chains and tensioners before the failure. Some cars have cylinder bore problems with the nickasil liners., but this is not as common. The 6 cylinder XJRs are hard to come by, mostly due to the fact that no one sells them on. The V8s are scary fast cars, IE you want it pointed in the right direction before you plant your foot. V8s are cheap enough, due to the problems, so if you want one, budget for the chains and tensioners right away. Unless of course the owner can document in writing (reciept) that the work has recently been done. Jag "upgraded" the tensioners a time or two before they got it right, so best that repairs were done professionally, and in the last year or two.