Welcome to MP3car.com! Sounds like a good start, and once you get it setup you will start to see what needs improvement. You will probably want to get the system to auto boot at some point, but I'm not sure that's so easy on a laptop without breaking into the case and doing some soldering. Probably easier to move to the next level and build a dedicated carpc to replace the laptop, but the laptop is good for testing phase. I use the wi-fi hotspot of my 4G phone, sometimes streaming Pandora, but mostly I play FLAC and MP3 files.
Hands free with the laptop might be an issue. No real nice solutions yet for BT and windows.