The Audi RS2 wasn’t the world’s first fast estate – the Volvo 850 T5 arrived a year earlier – but it is the most iconic of those early hard-hitting haulers. It was also Audi’s first RS model (yes, an estate) and because Audi didn’t have the expertise it needed for the project, was built with help from Porsche.

Quite a bit of help. The shells, adapted from the standard Audi 80, were constructed at Ingolstadt, then sent to...