I played around in the car a bit tonight and couldn't get things working. Sadly, my firmware doesn't even have any sort of client/bridge mode. It's got a ton of router functions (content filtering, port forwarding, etc.) but no option to bridge the WAN and LAN interfaces. So I'm stuck with a separate network segment and a WAN gateway, which isn't going to work out.

I could try to load OpenWRT on it, but I wasn't looking for a project within a project, and this was only going to be a temporary solution anyway until I can fully integrate my Raspberry Pi in the car, at which point I'll need a wired LAN with at least 2 ports on it for the RPi and the empeg to communicate.

So at this point, I'll probably just bite the bullet and install the WRT54G in my car again. It's going to be a clunkier install, but at least I get 4 LAN ports, and I know that client, bridge, and WDS all work.

I still think I'll get some use out of the mini router thingie, and even if all it's ever good for is a backup power source for my cell phone, it was worth the $18.