The long-awaited development kit for the new Compute Module is now available from RS (£170 including VAT and delivery) and Element14 (£152 including VAT and delivery). More information about the Module's capabilities and current compatibility with Raspbian is available over on the Foundation blog.
Parker Reed has written up his project to allow his car stereo to play audio received over bluetooth. He did it by hooking up a Raspberry Pi with a bluetooth dongle to his car’s cigarette lighter power socket (using a USB adapter) and then altering various start-up files. A 3.5mm cable from the Pi's audio jack to the line-in on his stereo completes the set-up. You can read how he did it over on Reddit.