After World War 2, Auto Union was reduced to a shell of its former self. A company that was in worse condition than Blockbuster once Netflix introduced streaming right to your living room. Auto Union scraped by for a little bit producing cars for school teachers, until they were bought out by Volkswagen. Once VW took control, Auto Union still produced cars for school teachers. What, did you really thing I was going to say something different? No, Auto Union was slowly reduced to just Audi the further time progressed. The cars Audi made were just front wheel drive VW's that were a bit more high-end, but still driven by school teachers. That is until Audi got the FIA to change the rules for the World Rally Championship.
Audi decided to take a gamble and create an all wheel drive system to put in the B2 80 and 90. The Audi Quattro all wheel drive system used a transaxle up front with the engine ahead of the front axle. A standard differential was put in the rear, driven by a driveshaft coming out of the back of the transaxle. A mechanically locking center differential would allow for 50/50 power distribution front to rear, and a mechanically locking rear differential allowed to the Quattro awd to get the car out of a bad situation. There would be only one place to test Audi's new creation, the Group 4 class of the World Rally Championship.
Audi immediately saw dominance on the rally staged with the combination of all wheel drive and turbocharging. The Audi became the team to beat in rallying. The Quattro created a need for a new class, Group B. Under Group B regulations the Quattro continued to see dominance against many well established companies in motorsports, such as Lancia and Opel.
The longer Group B continued the more the Quattro advanced and became a performance machine. The Audi 5-cylinder would scream and howl with its high boost pressure and power output. But the progression of Group B would make the Quattro less competitive as the super cars became mid-engined. Audi would continue to run the B2 platform because they did not want race cars that bared little resemblance to actual production cars. None the less, Audi continued to win races and stay competitive against the likes of Lancia, Peugeot, Ford, and MG.
Audi was able to be competitive in one of the biggest forms of motorsports of the '80s, and it showed in sales and the change in reputation. Audi was beginning to form a name for themselves as a company that builds all wheel drive performance cars. No longer a company that builds cars for school teachers. But, their reputation was still lacking in America.
To improve Audi's image in America, Audi decided to enter the 200 Quattro in the Trans-Am series. At first everyone laughed at the weird little German sedan, but then the little German sedan destroyed all. Like the honey badger, it ripped the manhood out of the American muscle it competed against. But that came to an end when the SCCA decided that anything all wheel drive or foreign was banned from competition (Quattro was too un-'Merican).
So now that Audi got banned from Trans-Am, Audi decided to annoy some more manufacturers by entering IMSA GTO. Audi entered a full tube frame version of the B3 90. Quattro all wheel drive allowed for the Audi 90 to have grip later in the race as the tires were worn out. Where the rear wheel drive cars were having a hard time putting the power down, the Audis could simply drive around the outsides of corners to overtake. The light turbocharged 5-cylinder also allowed for the Audis to keep up on the straights with the bigger engined cars. But with the added advantage of less weight, the Audis could brake far later than the opposition. This cemented Audi as a serious company in America, and helped boost sales. This also helped Audi gain motorsports pedigree in America and helped with sell S-Line Audis in the US.
If it weren't for the introduction of the Quattro, Audi would not have grown so fast. Audi would not be as popular as they are today. Quattro all wheel drive remains one of the best all wheel drive systems in the world to this day. With WRC, Trans-Am, IMSA, Le Mans, and WEC wins and championships to their name, you would be crazy not to consider Audi when looking for a performance car.