It's ok to speculate guys, the list on the site said it's not final as there are cars I've seen in videos of GT6 that aren't on that list either. The 2009 Saleen S7TT was spotted in the Silverstone video which melded Jann piloting the GTR and virtual cars were on the course two unique cars were spotted one looked like the HSV and the other was none other that the S7 Twin Turbo. So who knows what else is hidden in the game or coming to the game. That photo does seem to be telling of cars that may appear as the majority with the GT6 plates are already in the game, so it's probably safe to assume that PD has everyone of these cars in the game already or are lined up to be added. Let's just wait until we sit down and run a few laps in the game ourselves before we come back for more speculating.
I hope there is a community forum that we can request cars for GT and also let them know about problems and things that need fixing. Anyway I can't wait to take a spin in the M4, I'm still confused as to why BMW thought to bring out a 4 when the 3 is basically the same car, are they looking to make some size changes?