Given the absurd insecurity of the OBD II CAN interface on all modern vehicles, it seems insane to install anything there with a wireless interface on it.
Current generation vehicle electrical architectures are not network safe and rely on physical security.
There is a big trade-off here for the next generation; the electrical architecture will be COMPLETELY locked down, and end users will be locked out of making any updates to modules - something that tinkerers and home-brewers are at odds with. Read only access will still be allowed.