That's another manual than mine, yours states:
Car-Reverse ● Car Mode with reverse.
Reverse is activated only when the throttle stick is at Full Brake, returned to Neutral, and then reverse is applied.
I went through my manual several times, basic and advanced. Will try it again with your manual, maybe mine was outdated or something ...
The manual from the site states the same :
http://www.quarkbrushless.com/pdfs/U...sion2final.pdf