The Netgear WNDR 3700 router runs DD-WRT Linux firmware and serves movies via the HTTP and DLNA protocols. It also serves music via the DLNA protocol. Movies and music are stored on an attached USB hard drive. I wrote a script that builds an html file with all of the movies linked to the displayed cover art. This will allow a user to stream a movie without any special software.
The kids seamlessly browse movies stored locally on the Kindle Fire, as well as movies stored on the server, using the "MovieGallery" app, sold in the Kindle and Google app store. Music is served to the factory Honda head unit using Bluetooth streaming from a smartphone, which is attached to the router via Wi-Fi and pulling the music using the "BubbleUPnP" app (works via DLNA; also on the Kindle and Google app store).
The router is tucked into the nook in the trunk area of the Honda Odyssey. I created a cable that has the router power plug on one side and the power outplet plug on the other side. No inverter is required. The WNDR 3700 has a voltage regulator that can accept all voltages the the car may produce (11V-14V). I have a two-outlet power adapter that also has two USB charging ports. One power plug goes to the router, one USB charger goes to the hard drive, and a second USB charger is used to charge the Kindle (a cord is neatly run from the nook area to where my son's car seat is located).
Step 1: Purchase Components
Purchase a multi-use vehicle power adapter/charger. You are mainly looking for a two-port USB charger. The one I purchased is below:
Step 2: Flash Router