They had an unsynchronized H-shifter gearbox that requires double declutching on downshifts and careful power application given the huge turbo boost. The driver has to be able to use the left and right foot for braking and be able to press all three pedals at once momentarily when downshifting under braking (left foot on the clutch, right foot toe on the brake and blipping the throttle with the outside of the foot, misleadingly called "heel'n'toe").
Here's a really good clip of Walter Röhrl putting an Audi Quattro through its paces: https://www.youtube.com/watch?v=yyVHj3sHVHQ
Interestingly, the rally heritage of the 80's Audi engineering org was such that even their unmistakably family-friendly models had unusual, competition-inspired features. For example, my '89 200 quattro stationwagon's brake and gas pedals are very close together, precisely to ease heel-and-toe work during technical downshifts. She shares the same manually-lockable type 1 Torsen differential drivetrain with the ur- and sport Quattros, and is powered by a slightly detuned version of the turbocharged inline 5 racecar engine that dominated the rallies so unstoppably. And you can turn off the ABS :D
When you take her around some corners on a dirt road at speed, it's not hard to see why they called quattro "the unfair advantage."
That makes it sound like there are tractors that can do powerslides.
The only thing you really have to watch out for is popping a wheelie and crushing yourself under it. Imagine my surprise when I found out that real cars aren't like that.
One thing I really would love to see once is Bellof beating his 956 around Nordschleife with an average of 200 km/h... Sad that there is no real Video of it...
And I recall a few years ago listening to Marcus Gronholm - two-time WRC champ himself - asking his team for permission to drop out after his power steering failed.
Also the races were much longer taking place over about 5 days compared to the 3 day events nowadays. One event had about 40-50 special stages back then when now there are about 15-25 and most of those are just the same stages repeated. In addition they used to drive both day and night while while getting only a few hours of sleep per night. I'm sure current rally races are still pretty grueling events, but those drivers in the 80s must have been superhuman.
I'm still glad that things have changed. If they hadn't cancelled Group B the fatality count would have just increased. The cars were getting totally out of hand. Some rumors say that some prototype cars already built for the 87 season had close to 1000 horsepowers.