Here’s the things I would do for a carputer.

Objectives:

• Wifi Hotspot for other passengers
• GPS logging
• OBD2 logging
• Web Radio/Spotify client/iTunes streamer/MP3 player
• Bluetooth and BlueProximity (for keyless entry?)
• RFID reader (for keyless entry)?
• Parking sensor with image?

And things to install

1. Setup as per Bog standard install
2. Add a 3G modem
3. Turn into a wifi hotspot as per this post or this one
4. No-IP for remote access as per this
5. Add bluetooth support and BlueProximity
6. Setup autorun scripts like this