hi david and welcome to the club. having been a member of the forums for a few years now. I can tell you theirs not much to look out for having just bought a xj myself ,trading in the xk model. my advice to you is try and buy an approved used they now offer 2 years warranty. peace of mind, thinks to look out for are the usual check service history and if it has main dealer stamps phone them ask what work has been done on the car ect take a photo off the vin no. and give that to them they will tell you millage and any problems that have been fixed ect , the early xj sufferd from sun roof problems ie corroision on the runners but recalls should have sorted that out. also when selection gear mode in drive watch out for a lurch when engaged. could signal gearbox prob. apart from that theirs not much to watch out for start the car up and after 5mins check the smoke from the tail pipes nothing dark should be present. and if you buy then change the battery . jaguars are like most European cars and can get small elec glitches. a new battery soon sorts them out. other wise its the finest car on the market better than audi (my oldest son has an A7 s-line quarto it has 4 wheel drive) holds the road like !Removed! on a wall. ut the xj is better looking ,faster, better inside ect 7 ser bmw again nice car but not as good as the jag, merc s-class a better car than the bmw but the audi beats it, and te xj beats them all. enjoy, JAGUARS MOTO. ITS GOOD TO BE BACK. charlie