With Lotus deciding to make a big and heavy SUV, Caterham is now seen as one of the last bastions of lightweight sports cars. With the Seven 420 Cup, the endangered species is adding a new member as the company's most track-focused machine you can still drive on public roads. A first for a Caterham carrying a number plate, the new model comes with fully adjustable Bilstein dampers featuring no fewer than 10 stiffness settings selectable by hand.

Positioned between the 420R and the Seven race car, the new 420 Cup is motivated by a 2.0-litre Duratec engine producing 210 bhp and 203 Newton-metres (149 pound-feet) of torque to echo the Seven 420 with its identical power-to-weight ratio of 375 bhp per tonne. Output is channelled to the road through a Sadev six-speed sequential transmission to enable a 0 to 60 mph (96 km/h) run in 3.6 seconds. Flat out, it'll do 136 mph (219 km/h), which isn't particularly impressive, but getting there is what Caterham enthusiasts are after.

Gallery: Caterham Seven 420 Cup

The new 420 Cup sits on Avon ZZR or ZZS tyres but track-only, dealer-installed ZZR Extreme rubber is optional. It's visually distinguished courtesy of a race-style nose cone and a redesigned fuel cap. At the back, Caterham has installed new LED taillights. Go for the optional race roll cage and you also get a metal boot cover and sporty-looking side mirror caps. It can be configured in multiple chassis sizes and has a special exterior featuring translucent satin decals as well as body graphics.

The "interior" has also been spruced up a bit with an assortment of red accents noticeable on the seats, instrument cluster's dials, and the transmission tunnel. The naturally aspirated sports car remains true to its ethos by featuring everything that you need and nothing more to achieve a remarkably low weight of just 560 kilograms (1,234 pounds). That's roughly half the weight of a Mazda MX-5.

There's one major problem with the 420 Cup. Because of emissions regulations, Caterham can only sell it in the United Kingdom (no longer a member of the European Union anymore) and the United States. It costs from £54,990 in its domestic market while Americans will have to get in touch with their local retailer to obtain pricing details. A permanent member of the lineup, the new version will be sold exclusively as a factory build, meaning you can't buy it in kit form and assemble it yourself.

Caterham will have the 420 Cup on display in June at the Goodwood Festival of Speed. It's already taking orders, but production won't commence until early 2023.