'reverse' should not be triggered while trying to stop the car. Much better would be if one switches to reverse manually, via a "z" keybinding or similar (also see #3045029). After one switches to reverse vai 'z', <up> should accelerate (moving backwards) and <back> should, as usual, be the brake.
Unfortunately the current behaviour is counter-intuitive. I am often confronted with the situation when I try hard to stop the car, only for it to start going reverse and to become uncontrollable.
I'm not so sure about this. In my opinion it makes driving much easier not having to remember an additional key. It this get's implemented I would prefer it as an optional steering concept.
The current stopping-leads-to-backwards behaviour is completely intuitive to me and I prefer it.
As far as I remember, most games have a setting for this.
Note that space is hand breaks.