Classified of the week: Jag XJ series I

There's something extraordinary about the new Jaguar XJ. In one redesign, the flagship model's shrugged off its combover-and-Café-Crème image, dragged its fit and finish up to German luxo-box standards, and, somehow, it's still very much a... Jaaaaag.

And this week saw the biggest of the big cats get shot through with even more opulence - the Ultimate lunged onto the launchpad at the 2012 Beijing motor show, wearing champagne coolers, 335 horsepowers, two iPads, 20-inch rims, 20 speakers, hi-res screens... It's really quite special. Click here and look for yourself.

But there's a certain cad-like pomp to the original cars. Something that makes you feel like you're in a spot of bother with the Inland Revenue. And that you know a bookie that'll do you good odds on the 3:45 at Kempton Park. And this is one of them.

Launched in 1968, it was billed as "The finest Jaguar ever" by the company's founder, Sir William Lyons. It was a huge model for the firm, pretty much replacing four separate ranges (Mark 2, S-Type, 420 and 420G) in one fell swoop.

Customers got the choice of either a 2.8-litre or 4.2-litre straight six engine derived from the classic XK racing motor. And to keep their thirst sated there were two fuel tanks on each side of the boot. Very handy if you're too busy thumbing through betting slips to remember which side the filler cap's on - each wing got its own separately lockable one.

Which you can see on this one, currently up for sale in London. It looks like a bit of a peach, too. Its prosthetic-limb-beige leather is in great shape - no surprise considering it's only covered 44,000 miles - and the goldy-grey bodywork looks remarkably rust-free and shiny. Much like the britework.

What cost for such timeless decadence? This one's up for a piffling £3600.

Any TopGear.commers fancy a real Jaaaaaag?