Sweden has a specific category of vehicle known as an A-traktor which enables 15-year-olds to drive cars and pickups modified with a speed limiter of 30 km/h = 18 mph, and no more than two seats

The "type a" tractor has rural origins. In the 1940s, faced with a shortage of agricultural equipment, farmers were given the right to convert their cars for use in the fields. No permit was required. The only condition was not to exceed 40 km/h, then 30 km/h. Two decades later, as farmers gave up and bought real tractors, young people started driving them. A subculture was formed, associated with the "raggare" – often men, with a passion for mechanics and a love of big American cars.

 The national transport administration tried to oppose it, but to no avail. In 1963, it legalized the practice, allowing Swedes to register their cars as "type a tractors." In 1982, a red triangle with the letters "LGF" (for "langsamt gaende fordon," or "slow moving vehicle" in Swedish) was made compulsory on the rear of the vehicle.

https://www.reddit.com/r/europe/comments/14s16o3/swedish_teenagers_can_drive_from_the_age_of_15/#

https://www.lemonde.fr/en/sweden/article/2023/07/06/in-sweden-teenagers-can-drive-from-the-age-of-15_6044107_213.html

In March 2023, the European Commission published plans to update EU rules on driving licences which included a proposal to allow 16-year-olds to obtain a B1 license, enabling them to drive a car weighing up to 2500 kg as long as a speed limiter is fitted that prevents the vehicle from accelerating above 45 km/h. Negotiations on the final text of the new EU driving licence law are ongoing and the Commission, Parliament and EU Member States are expected to reach an agreement later in 2025. At the time of writing, the Swedish government is actively pushing for the age to be reduced to 15, to align with existing Swedish legislation on modified cars for teenagers known as A-traktors 

In Finland, in 2020, the government launched a plan to allow 15-year-olds to drive smaller cars (up to 1500 kg) fitted with a speed limiter set at 60 km/h – but the proposal for so-called ‘light cars’ was blocked by the European Commission. However, rather than outlawing these anomalies permanently, the European Commission decided to potentially expand the concept to youngsters across the EU

https://etsc.eu/the-eus-plan-to-allow-teenagers-to-drive-suvs-unaccompanied-at-16-is-a-fatal-mistake/

https://www.curbsideclassic.com/automotive-histories/regional-car-culture-explained-the-history-of-the-swedish-a-traktor/

In 1951, Nils Gustaf Håkansson signed up for the Sverigeloppet endurance race traversing virtually the entire length of Sweden – he was 66. He rode 600 miles to get to the starting line

Håkansson was there on race day in the saddle complete with mudguards, a headlamp, front basket and panniers. He wore a homemade bib with the number 0 on it.

After three days and only five hours' sleep, Gustaf was leading the field by more than 120 miles.

Due to the volume of racers, Håkansson crossed the starting line about 20 seconds after the race had started, but five days, five hours and 1,000 miles later, he crossed the finish line first – more than a day ahead of the next rider.

Eventually, with only 800 yards or so to go, Håkansson or "Steel Grandpa"; as he became known in the villages he'd passed through, came to an abrupt halt. But it wasn't sheer exhaustion that had stopped him – the old man's bicycle had suffered its first and only flat tyre.

Despite the albeit unofficial victory, a subsequent audience with the king of Sweden, and generally being showered in fame and honour, Håkansson's greatest satisfaction came from proving wrong the doctors who had thought he was better suited in a rocking chair than he was in a saddle.

The Steel Grandpa continued to ride bicycles until his death in 1987 at the age of 102

https://www.facebook.com/photo/?fbid=8252618271458925&set=a.366521386735359

Gunnar Olsson, a driving force in Swedish motor racing during the 1940’s and 1950’s establishing the first permanent motor racing track in Sweden, home-built the “Go-On II” around Jaguar SS and Alfa Romeo 6C components

The car was built on a home-built frame and was fitted with Jaguar SS differential/axle, radiator and wheels. The gearbox was sourced from the Alfa Romeo 6C and this was probably installed with the Alfa Romeo 2.5 liter engine when Olsson replaced the Lancia unit.

The bodywork of the “Go-On II” was made by professional coachbuilder Svedbergs and it appears to have been styled after the Alfetta 158 voiturette.

https://silodrome.com/go-on-ii-alfa-romeo-special-ice-racer/