"Set Brake as Reverse" node

I was playing with vehicle transmission and decided to make the reversing thing dynamic like, for example, enable brake as reverse if the player choose automatic. But unfortunately i can’t seem to find a fittting node. Is there any “Set Brake as Reverse” node or a set of functions that acts the same?
And also why the RPM goes to 0 when i hit the brakes?

And also why the RPM goes to 0 when i
hit the brakes?

If the vehicle is automatic, braking should cause a downshift. The RPM shouldn’t drop immediately.