I'd love to see this made by Olimex.
GPS tracker that can be plugged into vehicle's OBDII connector, so it could collect real time data from vehicle's CAN bus (e.g. DTC codes, fuel consumption) in addition to the usual stuff like coordinates.
For server side 'traccar' or 'opengts' can be used. Both of them are open source.
similar (commercial) product: meitrack tc68
Cheers.
...Or maybe just some kind of extension board for OLIMEXINO-STM32 with sim908/sim968 + accelerometer (MPU-6050?)