http://www.litewave.co.uk/glow_wire.asp

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12v Glow Wire Inverter, no Glow Wire: £13

Thats what you need mate, connect the feed to the box (cig lighter end - make sure you get the pos and neg right) to the illumination feed from one of the dash switches i.e. fog or heated rear screen (normally the top single wire on the switch) and the other to an earth.

The output end to the pins 1 & 2 on the pod (doesn't matter which way round these go as it's AC from there)

job done!!

ps. I'm assuming you have a mk5 van!!