Apart from the beefed-up brakes and suspension, there are super-big 19-inch wheels (up from 16 inches) rimmed with 235/40 tyres up front and 275/35 rubbers at the rear.
Aston Martin vice president and Special Operations officer David King said the model, which is claimed to have a ideal 50:50 weight distribution, illustrates the brand's "fun side".
Joining the all-new 715bhp DBS Superleggera flagship will be a one-off Cygnet commissioned though Aston's Q customisation service, which the firm has dubbed "the ultimate city car".
Despite it being priced at at roughly three times as much as the Toyota was, Aston Martin still predicted sales of around 4,000 per year.
Aston Martin builds V8 Cygnet 'ultimate city car'
Visitors to the 2018 Goodwood Festival of Speed, which starts today, can see the Aston Martin V8 Cygnet in action across the weekend.
Sourced from a previous-generation Aston Martin V8 Vantage S, the eight-cylinder engine sends 430-bhp (436-hp) and 490 Nm (361 lb-ft) of torque to the chunky rear wheels via a seven-speed Sportshift II transmission (also borrowed from the Vantage S) and a miniature torque tube.
With all its new performance add-ons, the Cygnet can sprint to 62 miles per hour (100 kilometers per hour) in just 4.2 seconds, and on to a top speed 170 mph (274 kmh). The dry weight of the vehicle is rated at 1,375kg, around 500kg more than in the regular Cygnet. The auto also features the previous Vantage's seven-speed automated manual transmission, limited-slip differential, and suspension. 380mm discs with six-piston monoblock calipers are at the front, and 330mm discs with four-piston monoblock calipers at the rear.
Showcased this week at the Goodwood Festival of Speed, this unique Cygnet has been heavily modified to accommodate the V8 engine from the old Vantage S.
On the inside, the Aston Martin Cygnet gets a fully FIA compliant fire extinguisher system while the seating is taken care of by composite, fixed back Recaro bucket seats with four-point harnesses. The steering wheel is removable, and the dash uses a Vantage instrument cluster.More news: Russians charged in DNC hacking case