Z-wave is wireless. There is a way I could use that system with relays. I couldn't find a stand alone 12v wire in module. But a manufacturer would not have much difficulty making these as z-wave boards are inexpensive.
From what I found out so far, with z-wave I would run Cat 5 from a signaling device to a relay at each light. The voltage over cat 5 would trip a relay for on-off. With that in place I can control the light from many locations, or programatically.
This saves me from wiring four way switches. and allows these lights to be integrated into my security system. I was going to build a little low power always on computer anyways. I will include a web server and wifi that would allow me to connect with the vehicle.