A quick homologation recap: When a car manufacturer wants to enter one of their creations in an international racing competition, they're sometimes required to produce a limited run for public sale.
This doesn't apply so much to cars that already existed. The Ford Escort, for example, was a road car long before it went rallying. Sometimes though the race car comes first, so if you're ever lucky enough to see the likes of a BMW M1 or Audi Quattro in real life, then you probably ought to doff your cap to the homologation gods.
This video is cool AF!