The R129 was the fourth outing for the SL-Class, launched in 1989, and acts as a neat showcase of how the scale of cars has evolved; seemingly large for a roadster in period, it actually feels pretty compact in today’s traffic.

The crisp styling has aged extremely well too; the Bruno Sacco-penned lines marked a sea-change from the 1970s styling hangover of the brand, ensuring that the R129 remained in production for over a decade while appearing smartly contemporary throughout.

It was also, as you’d imagine, a real technological powerhouse, with pop-up rollbars, self-lowering active suspension on some models, and all manner of passive safety systems.

The third-generation of the R129, available from 1998-2001, represented the last of the breed before the model was replaced by the R230. Known domestically as ‘Mopf 2’ (or ‘second facelift’), these later cars are identifiable by their reshaped front and rear aprons, body-colour door handles, standard-fit third brake light in the bootlid, and redesigned door mirrors.

The lights were reworked on end-of-the-line cars too, with Xenon projectors at the front and softer monochromatic clusters with fewer ‘ribs’ at the rear. There were engine improvements as well and, as you can see with this car, some pretty fabulous spec options…

The ‘Designo’ programme essentially allowed buyers to custom-build an R129 to their own spec without adding too much complexity for Mercedes-Benz at the production line, and there were a variety of special paint shades and interior trim options on offer. As an extension of this, the SL Designo was offered as a UK-market model, and as is typical of the nature of run-out specials, the proverbial kitchen sink was thrown at it in terms of options.

The SL Designo was offered in three colours – Alanite Green, Mystic Blue and Almandine Black, and this car is an example of the latter. As you can see, it’s not really black at all, but actually a magnificently vibrant deep metallic purple. The car also came with the desirable panoramic glass hard-top, a machined aluminium dash, 18” split-rim alloy wheels, and much more besides. A truly delectable and collectible example of an extremely rare SL.

There’s a robust and impressive file of documentation with this car. The original books and manuals are here, with the service book fully stamped by specialists throughout its life.

The online MOT history verifies that the low mileage of 75k is genuine, and there’s a sheaf of invoices on file both from Mercedes-Benz main dealer and marque specialists.

There were some excellent spec choices made here, for sure. The Designo two-tone Bordeaux leather is sublime, and the front seats are 8-way electrically adjustable and heated, all of which is working as it should. (It’s impressive to note how the front headrests automatically lower themselves when the front seats are moved forward while tilted – those engineers thought of everything!) 

The leather is in lovely condition with just a little patination to the driver’s side bolster and base. The rear seats are in very good order, and their seatbacks fold down to provide handy extra storage.

The dash is finished in machined aluminium, and all of the gauges are working correctly. The electric windows work well, and the factory-fit Audio 10 stereo system is still fitted (with radio-cassette head unit and CD changer in the boot). The slide-back centre console cubby reveals individual storage for your cassette tapes. The carpets are excellent, and it’s all proper inside the boot too, with the original warning triangle, first aid kit and spare wheel in place.

This SL’s calling card is its remarkable paint colour, and the Almandine Black really does sparkle with a deep purple lustre in the sunshine. It’s in superb order throughout, with no obvious scuffs, scrapes, dings or blemishes to be found. 

This car came with the panoramic hard-top option, which is a very sought-after thing (with a glass roof panel with retractable blind), and this is in superb order. The roof releases as it should and, once carried away, the soft-top raises, latches and lowers perfectly too.

This model benefits from the split-rim 18” alloy wheels, which look terrific – they’re in great condition with no kerbing, and wear matching Continental tyres.

The light lenses and window glass are all in good order. There’s a smattering of minor stonechips to the lower section of the front bumper, but aside from that it’s in absolutely beautiful condition throughout.

 

The third-gen R129 models received mechanical upgrades across the range, and in the case of the SL 320 this meant that the 224bhp M112 3.2-litre V6 engine revved out to a higher redline. The electronically-controlled five-speed auto is an eminently appropriate companion, and its 3.45:1 axle ratio means that it’s the sort of cruiser an SL should be as well as having that new-found sporting edge.

All is working as it should here – the engine fires happily on the first turn of the key, idles smoothly, and pulls with a really vivacious urgency through the rev range with the right foot firmly planted. It’s also supremely comfortable to waft in and shrugs off speed bumps with casual aplomb, testament to how well engineered the suspension is. 

The brakes are strong, the steering is sharp and well assisted, it’s all very pleasing. A late-model R129 doing exactly what it ought to.

There’s a lot to love about the R129 model in general, with its generous equipment levels, smooth and supple ride, muscular engines and ineffable style. But this R129? This one really is something else. 

The Designo spec is extraordinarily cool, the fabulous paint beautifully complemented by the splendid interior, and the style is packed up by proven substance. It’s a low-mileage car with a robust history, and will surely give its next keeper many years of chic and joyful motoring.