I'm at 62% now after 10days. Finished Beginner/Amateur/Endurance and half of Profesional.
Got 7 F1 cars now :-).
I started with the Toyota Sprinter Trueno, then Mustang SVR, then Skyline V spec II, the F1.
S license took me just 3 hours to complete (had 47 golds in GT2).
Maybe my luck was the first car to win endurance race (Super Speed) was a F1 car.
And still enjoying it every minute... best racing game ever (And I played a LOT of racing games mostly PC games).
Finished GT 2 in about 2 weeks. GT1 I don't remember any more... :-)
Bought the game on Saturday and played all night 'till I noticed I didn't had a memory card LOL and so kept playing 'till monday morning to rush to the playstation shop...
Still got one week to finish the game before stating to work again...cheapest vacation ever :-)
Cheers.