Trying to hardwire V1 into 318is...

[Funkmasta]

RTFM and tell us what each wire in the phone line is supposed to be - off hand, I would say a radar detector would need +12V and ground - what else is there?

I believe the other wires are for data transfer/remote display

[ak96ss]

Yeah, that's what I figured, which means he'll need to run a cable down the a-pillar anyway, or cut the existing wires at the display panel and at the base of the a-pillar to use those. And be ready for whatever issues that may raise.

Assuming you aren't using the remote display, you really only need the +12V and the ground. You'll have to ground it somewhere else, as there is no harness ground up there. You could probably just ground it to the windshield frame, but I don't know that I'd be drilling holes up there, myself. Anyway, tap into the green/white wire for +12V, ground it, and you're done.

EDIT: Assuming the V1 has US-standard wiring, red should be +12V and black should be ground, but, again, check the manual!

[Funkmasta]

Wait, did you cut the phone cord? The standard hardwire kit has a junction box that has only the power leads...