Although it has aged rather elegantly, the Jaguar XJS was long considered, to borrow a British expression, a right minger. That led a number of enthusiasts to create their own versions, like this 1990 XJR-S “Monaco.”

Created by PBB Designs, out of Bristol, U.K., the car was the brainchild of Paul Bailey. A former aircraft engineer, he found himself doodling what he considered to be a more attractive version of the XJS, one day. Because he was an engineer, he was careful to draw one that it would be possible to eventually make.

“There’s no point in dreaming up a design that couldn’t be built,” Bailey told Jaguar Quarterly in 1992. “I wanted my car to be exactly as I drew it.”

That included an extended hood, a new hood, and modified wheel arches to accommodate bigger alloy wheels, all of which he eventually decided to put into production. Although he initially got in touch with Park Sheet Metal, the same shop that helped produce the Jaguar XJ220 concept, to create steel body panels, he eventually decided to make the add-ons out of fiberglass.

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According to Bailey, the spirit of the E-Type lived in the car that he created, and while that may be true, it’s fascinating, with the benefit of hindsight, to note how forward-looking the design was.

I would argue that, in the headlights, the grille, and the rounded body panels, this predicted many of the design elements that would come to define the Jaguar XK8 several years later. I will admit, though, that the later car has an overall more cohesive design.

Bailey’s business only lasted long enough to produce a total of 12 vehicles (though there is some dispute about that number), with the first two allegedly being sold to the Sultan of Brunei.

This Monaco, though, actually started life as the original prototype and was used as the company’s poster car, appearing in magazines such as EVO. Originally sold to a Scottish oil executive, it then made its way into the hands of the current owner.

In 1999, longing for a little extra power, he turned to another Jaguar expert, Paul Hands, for some help. Together, they decided to take all the PBB Design parts off the car, and install them on a later model JaguarSport XJR-S.

That means that the car now has a bigger 6.0-liter V12 that was originally rated for 318 hp (237 kW/322 PS). It also has a modified intake system, dual exhausts, and TWR-developed suspension with Bilstein shocks.

Now offered for sale through Silverstone Auctions, this utterly unique 1990 Jaguar XJR-S Monaco with its fascinating history can be yours. Estimates suggest that it will go for between £18,000 – £24,000 ($21,700 to $28,933 USD at current exchange rates).