I've done some quick searching to no avail.

I'd like to have the possibility to look around the car interior with my mouse while driving the car with my steering wheel. To be more precise, I imagine it like this:

I drive the car around the track as usual, but I need to look a little to the right let's say, so I hold the LMB down and move the mouse. After releasing the LMB, the view seamlessly returns to its original position.

This could also be later incorporated with some interactive car controls on the virtual dashboard, MS Train Simulator style.

What do you think?

try this out Breadfan.

Should do what your asking for without holding down any mouse buttons.

Just move mouse around to where you like,
& to center view again simply press RMB once.

Enjoy....

Ooh,just remember if your using windowed mode(Shift+f4)
You have to clip mouse to window.(in---options\screen menu)OR(CTRL+C)

Oh goody, thanks a lot

But I still suggest the interactive dashboard :P