Dave 'st' Sabre just published his vintage Formula Ford mod for rFactor, simulating a wingless Lola T340 from the classic 1973 era.
An update with better sounds, gearings etc. is in the works, and the first version is already quite enjoyable to drive.
Available here, among other places:
UPDATE: Now updated to V2.0, with many little improvements, including adjustable brake balance/strength, more realistic average top speed of 140mph, better sounds, fixed gearbox, more realistic tyre temperatures etc.
Edited by Raido, 09 July 2010 - 00:50.