In game options, change the mirrors to 'virtual'. That'll give you a floating rear view mirror at the top of the screen in any of the in-car views. That is, if I recall correctly.
I think its just 1 Marcus for Race 07, but if its set to real, then virtual wont work, it has to be set to one or other and the 1 function is basicaly on or off
From what I have seen in game, no, but that is not definitive as I have no clue about editing the .plr to make things work, or any other .ini file that might have the info.