I have an Apple Airport in my Miata hooked to my mk2, and it works. The airport (or at least mine, YMMV) uses a PSU inside the box (LM2596 from memory) which is fine from 7v->around 40v, so this just comes from the accessory feed.

The main problem is that the airport is a server, not a client - the software in the box won't talk to another airport. I just use a pcmcia card in my machine plus the airport in the car & with a development version of emplode which runs over a socket connection it all works just like you'd expect it to.

Lucent *do* do a client ethernet<>wireless adaptor which looks like it's the same hardware as the airport, just with different software. It's also 3x the cost...

You don't need the mac, the out-of-the-box config will work. Remember it's a bridge, not a router, and so as default just sits there working with MAC addresses. My mk2 is static-ip'ed and the bridge is just transparent. The airport will dhcp server on the wireless side and so dhcp's my laptop's wireless card.

Hugo