I don't know if I'd describe it as "TinyURL for your car", but after reading about what it does the description makes sense. It might be hard for people to initially "get" though.

Where I see some future potential is in fleet management for smaller fleets (think your local plumber that has a couple of work vans, or maybe a small taxi company, etc). Being able to inexpensively monitor the locations of the vehicles, how far they've been driven, whether there are any trouble codes, etc, might have potential. I could also see potential for having maintenance reminders built in (e.g., set up the maintenance schedule, have it remind you say 500km, 250km, 100km before maintenance is required).

All of that would require some user management stuff and vehicle management stuff, but that's just software. You've got the hardware side of things taken care of already.