I have some ideas for a plug-in, but no coding experience on android.
The base idea is to provide a complex and rewarding feedback on driving stile.
I drive an hybrid car, which is a system with lot of custom parameters you can collect to evaluate your performances.
Aside from the classic MPG indication, you have to consider battery level, quantity and flow of charging current, braking style.
The plug-in should be able to collect and synthesize those PIDs in one or more “driving ability” gauges, so, on a given track, you can measure your driving style.
GPS integration could geo-locate your best tracks and rank your efforts inside the community of your neighbors.