The way Bluetooth works on SailfishOS devices is that SailfishOS itself is in charge of handling bluetooth devices, and if it is some standard device (audio, input), it forwards the standard interface to Android AppSupport.
This doesn’t work with custom things like CAN bus / OBD-II spying devices.
It only works with standrad peripherals, like bluetooth speakers and headset (SailfishOS handles the Bluetooth connection, and then Android only sees a generic audio output) or keyboard (SailfishOS handles the Bluetooth connection, and then Android only sees a standard input).
Even with those devices, the Android Apps don’t talk directly to the bluetooth interface (e.g. it’s not possible to upload custom equalizer settings to bluetooth speakers, it’s not possible to upload custom “touchscreen emulation” macros to a gamepad, it’s not possible to upload firmware update).
So, in SailfishOS, it’s not possible to let your (already privacy-screwing) car to share part of that tasty customer spying data with your insurance company so that they to can profit and earn tons of money by reselling it elsewhere.
For the location tracking, you would need to install something like microG and additional NLP providers to assist the GPS-tracking. (Would also work by installing the official Google Play Services, but I have no experience with that).