I absolutely love the fact that Volkswagen (with its Golf Clubsport S), Honda (with its AWD Civic Type R), and now Subaru (with an out-and-out racer) continue to make assaults on the 'Ring with production-based, factory-backed cars.
Ain't no stinkin' 0W-20 weight motor oil in those sumps!
I've always felt this was one of the better hill climb videos. What is really amazing is Alain Castellana who is driving, was 57 years old when this video was shot! And no shifter paddles. His hand goes to the stick for every gear change.
Well, this was a custom race car with 600 bhp. Still, this puts a Subie into some very elite company. This car ran a little faster than a considerably more powerful Ferrari.
That this purpose-built race car could run quicker than a street legal Ferrari, is simply comparing apples to oranges. For a meaningful comparison, it needs to be compared to other purpose-built race cars.
The Ferrari that was slower around the 'ring than the Subaru was also a non-road legal vehicle which made 720 bhp and weighed less than 3000 pounds. This was actually also a faster time than Lauda's pole position qualifying lap for the 1976 German Grand Prix in his Ferrari 312T, which IIRC correctly was the first sub seven minute lap of the 'ring.
The 'Ring, has changed substantially over the years.
As for the cars, I don't know the details of the ones being compared. What was obvious from the video, is that the Subaru was a very long ways from production car trim. Moreso than the Ferrari you mentioned? who knows?