anyone know how to bypass without having to buy the 20$ part? I heard relays may work or possibly just grounding the wire but I was wondering if anyone tried it before or knew anything

I have a 92 jetta 8v 1.8L ok i got this Kenwood Head Unit and i have the manuals for both the jetta and the head unit (below) ManualsMania - Kenwood - KDC-S2007 - kdc-s3007.pdf - Owner's Manual - English 1985-92 Volkswagen Jetta Stereo Wiring Information i and trying to wire it up and im not...