You need to just wire it up direct and not use an adapter.

By adapter, I assume you mean something that wil allow you to just plug it into the VX harness.

You might find that at a car stereo store. Ask for the install manager or a sales person and tell them what you want to do. Ask if they have any kits or adapters that would help. I doubt it... the VX was a short production run as far as cars go.

Good luck.