Laptop audio played through car speakers using bluetooth?

I have lectures on dvd that I want to play on my laptop (e.g. using Windows Media Player) so that the sound plays through the car speakers. Ideally, the laptop would pass the audio to the car wirelessly, via bluetooth connection. While I can get my (vista) laptop to pair with carmediaplayer, my computer says "Windows was unable to install your Bluetooth Peripheral Device Windows could not find driver software for your device."

Anybody able to play audio off their laptop wirelessly? Possible?