Ignorance must come into it as well, though. Many keyers clearly have no idea of the value of the vehicles they're defacing. Would whoever ran their front-door key right down the side of this week's perfectly innocent Jaguar XJ8 reconsider their action if you told them it was only worth £995?
It's especially annoying when the sheet metal being butchered belongs to an X308, arguably the last great old-school Jag. In 1997, the arrival of the V8-powered X308 signalled the end of the Jaguar straight six. Although there's little to beat the sound of an open-piped Jag six in a C- or D-type racer, the criteria for success in the XJ were different. In an XJ, noise was something to be suppressed rather than celebrated.
Engine-wise, most of the early XJ8's issues can be traced back to the inappropriate use of plastics instead of metal, a practice that was hardly unique to Jaguar at the time. Presumably the thinking was that useful amounts of weight could be saved by binning metal wherever possible. Unfortunately, the laws of chemistry stepped in to wag an admonishing finger at those manufacturers who went down this route. Jaguar's linerless Nikasil-coated bores were exposed by the high sulphur content fuels that were prevalent in the late 1990s.
Early cars like this one would have started out with plastic cam chain tensioners. A rattle or knock from the front of the engine on startup could mean they haven't yet been replaced with sturdier metal items. Same goes for the X308's plastic water pump impellers and thermostat towers: you'd want them to be aluminium. The stat tower on our Shed is, but there's no info on the pump or the tensioners having been done, or indeed on the Nikasil issue having been resolved by the fitment of steel liners.
ABS control modules can fail. They're very expensive and (according to Jaguar) non-repairable, but the old lags will laugh at that and point triumphantly to their soldering guns. Throttle bodies and position sensors can play up. The bodies should have been replaced under warranty, but we're 20 years into the life of this car. It's a good idea to give any XJ8 a decent run to see how these parts perform with a bit of heat in them.
Rashly, Jaguar pronounced the X308's ZF gearbox to be a 'sealed for life' unit, but a thousand and one online posts will tell you otherwise. Changing the oil and filter isn't as easy as you might hope, but if you're planning on keeping an X308 for a while then you might prefer the inconvenience of carrying out that service over the long-term jerking or thumping through the drivetrain and eventual gearbox failure that will occur if you don't.
Inside, there really isn't too much to worry about. The lacquer on the wood trim pieces can craze, but despite what your foolishly grinning mates might like to tell you, the X308's electrical system is not the motoring equivalent of a nest of enraged vipers. Besides, the XJ8 is modern enough to have an input socket for diagnostic code-readers so if anything does go wrong you won't be left scratching your head and wishing you'd never been born.
Check that the 'S' sports switch at the base of the J-gate gearshift housing isn't sticking. The backlights for the clocks, radio and aircon display can conk out, too, but the electric seats (cloth in this case, so quite unusual) are pretty reliable. The auto-dimming seems to have gone squiffy on this car's rear view mirror, as it can also do on the door mirrors if they're so equipped. Not a massive problem, or at least, not massive enough to justify the cost of replacements.
It's not perfect, then. A gap opened up between the 2009 and 2016 services, but it's back on track now, and there are early signs of floor rot. However the near-complete family ownership, plus brand new MOT, should mean you've got at least a year's legal luxury motoring in store. Treat yourself while you still can. They won't be around much longer.