This is deliberately in the Sportscar forum, so please don't put me in the Armchair Enthusiasts section Ayse!
The long rumoured WSC sim has now appeared, but in a different incarnation. If the hype is to be believed, GPL has a spiritual successor. Many of the cars that have been featured on the site are late 60s, early 70s sportscars.
Check out the link below and the thread 'Racing Legends' in Armchair Enthusiasts.
http://www.west-racing.com/