Jaguar has been long-defined by the E-type and original XJ. Both cars seem to have hung over the company like a couple of family portraits. For decades, company bosses have seemed unable to allow new models to stray from an obvious family resemblance.

Then again it’s difficult to introduce new design ideas to a brand, especially one with a history as defined and distinctive as Jaguar’s.

Attempts were made. In 1967 Jaguar rolled out the Malcolm Sayer-shaped mid-engined XJ13 prototype racecar. In theory, design ideas from this car should have been fed into future Jaguar sports cars.

Instead we got the uncomfortable XJ-S, with its flat rear screen and flying buttresses, hinting at a mid-mounted engine it didn’t posses.

While the XK8, which replaced the XJ-S, did successfully build a new Jaguar big coupe aesthetic, the company’s saloon cars were still stuck in the design mire, unable to escape from their Mk2 and XJ heritage.

There’s little doubt that the S-type and aluminium XJ saloon were massively missed opportunities. Only under Ian Callum did Jaguar finally hit the executive middle market square on with the XF, if for no other reason that it is simply and tastefully modern (with, perhaps, more than a nod to Lexus).

The XJ, though, is a much harder call. The company’s flagship has barely changed since it was launched in 1968, a radical and game-changing machine.

Which is where the XJ220 steps in.

18 years ago I was arguing with a remarkably intellectual external examiner on my post-grad course abut the importance of concept cars such as the XJ220.

He was a student of the late 1960s, when design was seen as science and aesthetics were something that evolved from a design’s fitness for purpose.

I was using the XJ220 as an example of the need for rolling sculpture to oxygenate a company’s styling portfolio. I made a bet that the XJ220 would eventually influence a Jaguar production car.

Maybe I’m finally going to win it.

Look at our XJ spy pics and mentally check the steeply raked windscreen and low roofline running into a very shallow rear screen. Then think of the fully glazed roof and the shallow side window graphic.

So when the XJ’s disguise is whipped off, I’ll be looking for XJ220 DNA in the XJ’s glasshouse treatment.

I’ll either finally win the bet with the external examiner or I’ll get a text message from Ian Callum telling me not to be such a pillock.