[1][2] One of his early motorsport achievements included winning the Deutsche Bergmeisterschaft (German Hillclimbing Championship) in 1962 with a Ferrari 250 GT SWB Berlinetta under the pseudonym Robert Frank.

[1][3][4] Up until the end of the decade, König raced a variety of cars including the Lola T70, various Fiat Abarths, Borgward Isabella TS and Ford GT40.

[7] The foundation of Koenig Specials began in 1974 when Willy König bought one of the first Ferrari 365 GT4 BBs in West Germany, but was dissatisfied with its performance in comparison to the sports car racers he was accustomed to.

If this wasn't enough for the owner, Koenig offered a twin-turbo conversion that consisted of a pair of Rajay turbos and intercoolers, which produced a total of 620 bhp.

With a large spoiler and every body panel (with the exception of the roof and upper front bodywork) replaced, the car was able to reach a claimed 0–60 mph in 3.9 seconds and a top speed of 206 miles per hour (332 km/h).

[6][11] Perhaps Koenig's most notable project was their work on the successor of the 512 BB, a modified version of the Ferrari Testarossa that debuted in the 1985 Frankfurt Motor Show.

[16][17] For those who wanted extra power, there was the Competition Evolution quoted at 1000 PS DIN, claiming a top speed of 230 miles per hour (370 km/h) and an estimated 0 to 60 mph in 3.5 seconds.

[13][15] The company additionally branched out into offering kits or full conversions for other makes of vehicles, such as Mercedes-Benz, Jaguar, Porsche and Lamborghini.

[20] A complete rework of the Ferrari 348 was offered which included twin turbos and a full widebody conversion with a wing similar to that seen on the F40 (hence "F48").

[21][23][24] Koenig's reputation grew so much that it divided the opinion of Ferrari fans, disagreeing on even the removal of the side strakes on the modified cars.

[25][26] An article in Sports Car International claimed that they were (likely) to spark the widebody conversion trend of the 1980s,[22] additionally they were described by Auto Bild as "Germany's wildest tuner".