Do I need an adapter for the speed/ brake/ reverse in my R32? I have heard both ways.

Advise?

what do you plan on doing?

I have a 2004 VW 2.slow

are you referring to the vag-com cable? you don't need that unless you plan on tuning the car. don't need it for anything relating the stereo.

No, you don't need them.

Brake and reverse should be available outside of CAN BUS.

VSS may or may not be (on my A3 it isn't, and although the same platform, mine is newer...). If you are installing 900 or 90 you may want to get one.

If you have steering wheel audio control and want to retain those, you'll also need a CAN BUS adapter for that.

Otherwise, no...