What I find surprising is the fact that drivers dominated the scene in rather limited timespans. Take a look at Makkinen, who's success vanished with the advent of Petter Solberg, people like Sainz, Grönholm or possibly even Loeb have been superseded after a certain time of success.

It appears to me that the mental capacities and reflexes demanded in rallying are much higher than in road racing, where one might practice the track and car's behaviour to a certain extend. Could it be a matter of lucky circumstances, building a car that only one single driver can perfectly adapt to? Very unlikely. Possibly the development speed amongst those manufacturers is still much slower than in other motorsport categories, submitting each one with a fair share of success once in a while? Obviously Subaru has a hard time climbing back to the top right now, this shouldn't be the sole reason though.

Curious to hear your answers.