The Cygnet is anything but a typical Aston Martin: it’s a rebadged version of the Toyota/Scion iQ, a tiny city car sized to rival the Smart Fortwo.

Aston’s foray into the city car segment came about because the company needed an efficient car to help bring down its corporate average fuel consumption in order to comply with stricter European emissions regulations introduced in 2012. To that end, it teamed up with Toyota to sell a modestly restyled version of the iQ through its European dealerships.

Naturally, an Aston Martin with a 1.3-litre engine that makes just 97 hp is pretty laughable, but one of the brand’s customers thought it would be fun to endow a Cygnet with the kind of performance the brand is better known for.

And that is how this particular Cygnet came to house a 430-hp, 4.7-litre V8 from the Vantage S.

Somehow, Aston engineers managed to cram the V8 under the Cygnet’s tiny hood — which required no alterations — by modifying the car’s bulkhead and transmission tunnel. They also welded a roll cage to the car’s structure and worked up subframes for the powertrain and suspension that are based on those from the previous-generation Vantage.

A short, custom-made torque tube and driveshaft take the engine’s power to a limited slip differential at the rear wheels. It may be worth mentioning here that the Cygnet starts its life as a front-driver; the conversion to RWD allowed Aston to give this Cygnet perfect 50:50 weight distribution.

With its new heart beating loudly through a custom built dual exhaust system, this Cygnet scoots from 0-96 km/h (60 mph) in 4.2 seconds — quicker than the V8 Vantage S — and to a top speed of 273 km/h, nearly 100 km/h faster than the four-cylinder Cygnet is capable of. Braking is handled by 380-mm front and 330-mm rear brakes clamped by yellow calipers painted to contrast with the green bodywork.

Aston gave the V8 Cygnet its official reveal last weekend at the Goodwood Festival of Speed in England.