Debraj have shared his latest project details where he built an OBD reader. As his car (Hyundai -i10) uses CAN-BUS communication protocol naturally it is based on it. To be more specific CAN runs at 500kbps speed and uses 11-bit ID.
The reader is based on dsPIC33FJ128MC802 microcontroller and MCP2551 CAN transceiver. Information is displayed on standard four row alphanumeric LCD. His further plans are to add SD card to collect some interesting data while driving.