If you put in the 1.2 patch, this comes directly out of it and might be worth a shot, as well:
 
ALTERNATE MIRROR
 
The patch adds a new mirror option to the game.  While driving, you may use the M key to toggle between the original 3-pane mirror and the new single pane convex mirror.  Your mirror preference will be saved from your previous single player race or testing session.
 
The mirror parameters can be specified in the N3.INI file. For the standard 3 panel mirrors the following lines are required for editing, and these values are the default parameters.
 
      X     Y     Z     Yaw(degrees) ScaleY       ScaleZ      ScaleDepth
MIRRL 0     0     8000  -102         150000       250000      93592
MIRRC 0     0     8000  0            150000       275000      458888
MIRRR 0     0     8000  102          150000       250000      93592
 

For the new convex mirror:
 
;       X    Y  Z     Yaw(degrees)  FOV(degrees)  ScaleZ  ScaleDepth
MIRRX  -3000 0  7500  10            200           270000  65536

