Both the full car shape and cockpit shape are always loaded.
The code path handles explicit rendering of mirrored objects
(to a level as set in the menus).
So, its possible the mirrors could:
a) no reflect your own car at all
b) reflect the cockpit model
c) reflect the full car
d) reflect a 'dummy' sprite to represent your car.
I can't remember which of b/c its set up to support - I think just c as it happens - so you shouldn't be able to cockpit model reflected, regardless of what you author into it.
The settings file suggests the option of fullcar reflection is only available for T-Cam, though I can't think why i'd have made this restriction.
BTW, the 'context' setting was specifically added for the situation where there was an engine fire and it looked odd in the reflection just hanging in space.
Jason.