Sorry Paul (or whoever you are this week!), somehow missed pasting my reply in above ... doh!
It wires up as shown in the photo. Black box is the transformer. It plugs into 230v ac and converts to 12v dc. Black wire from the transformer supplies 12v dc to the controller which is the white box. The controller has a white wire which connects to the LED strip (they supply a little adapter because both plugs are female for some reason). The other white wire from the controller (the one with a black blob on the end in the photo) is the Infra Red sensor which receives the IR signal from the remote. Ideally it needs to be in line of sight of the remote, but it will work on reflected IR, just not as reliably.
To run from a car, all you have to do is discard the transformer. Both in the picture and the set I have, have a "cylindrical blob" in the 12v wire from the transformer. I have no idea what this is or what it does. Perhaps some one who knows their electronics might offer an answer, but I'd suggest you include it in your system, so cut the 12v dc wire between the transformer and the cylindrical blob. You then need to work out the polarity, so with a multi meter, check the circuit between the centre pin on the 12v plug which goes into the controller and where you cut the wire ... that will be your positive feed, the other will obviously be negative. Wire up via an 8 or 10 amp fuse and you should be good to go.