"Back in the day" race car transmissions were unsynchronized and manually shifted ususally with an h shifter. To the best of my ability to research (without spending money) these transmissions were double de-cluthched on downshifts and upshifts were performed with only a throttle blip to match revs and without disengaging the clutch. (Reportedly another upshift technique was to merely tap the clutch pedal to just slip it a little bit to match revs on the upshift?) Such race transmissions are now called dog boxes or crash boxes and are built with sturdier teeth more widely spaced. Dog boxes are stronger than the synchronized transmission in your daily driver. A web page explaining dog boxez is
http://automotivethinker.com/transmission/dog-engaged-transmissions-aka-the-crash-box-and-dog-box/. I found a discussion on shifting on the Nostalgia Forum at Autosport where the consenous was the most common shifting technique in F1 was what I have repeated above (at least before the advent of paddleshifting automatics and LFB) It was also reported that Gahram Hill did not skip gears when downshifting, even at Monaco! Also of note I believe Nascar still uses such transmissions.
I would like an option for rF2 to model a dog box.
Sam