It’s not uncommon to see trends form within the automotive industry; see: SUVs, Coupe crossovers, and performance pick-up trucks – if someone wants one, a carmaker will build one. In recent years, speedsters seem to have latched on – McLaren made the Elva, and Aston Martin the V12 Speedster, among many others. But for some reason Mercedes-Benz, or rather Mercedes-AMG never seemed at all interested in making one.

So say you’re a multi-billionaire Mercedes-AMG collector, and really want a made-in-Affalterbach topless Speedster-style roadster, what can you do? You build one yourself, of course – and that’s exactly what Ronald Bussink did. Say hello to the Bussink GT Speedlegend.

Don’t think for a moment that its another backyard hack job, either, because the GT Speedlegend is actually built by the guys at HWA, who ran currently runs Mercedes’ DTM team, and Formula E team two years ago. Besides, HWA boss Hans-Werner Aufrecht was also the founder of AMG, so this is pretty much as authentic as you can get without actually being AMG.

Inspired by the Mercedes-Benz SLR Stirling Moss and Mercedes F1 cars, the Bussink GT Speedlegend took a standard Mercedes-AMG GT Roadster donor car, and replaced its convertible roof mechanism with what’s called a Speedbow, a F1 halo-inspired pillar that runs from just in front of the tiny windscreen, all the way across to the roll hoops just behind the seats.

The carbon fibre beam helps increases rigidity, while also stripping off nearly 100 kg in weight, lowering the centre of gravity which aids handling and stability. Other bespoke items on the Bussink GT Speedlegend also include the carbon fibre louvre on the front wheel arches for enhanced aerodynamics.

Underneath the bonnet, the speedster comes as standard with a 4.0-litre twin-turbo V8, which in standard form on the AMG GT R Roadster, churns out 585 hp and 700 Nm of torque. On the Bussink GT Speedlegend however, power output has been tuned up to 850 hp, which we presume will make it significantly faster than the 3.6 seconds century sprint time of the GT R.

Only five units of the Bussink GT Speedlegend will ever be built, but if you think that you’ll have a chance to own one, tough luck – all five units have already been spoken for, presumably by Bussink’s own millionaire friends. Although, Bussink did say that there’ll be more projects coming in the future between him and HWA, so perhaps you can look out for that.