Just in case anyone needs it, here are the instructions on resetting the GROM BT3 radio adapter if you're having trouble getting it to pair with your bluetooth device. I know it works on Disco IIs, not sure about other models. Anyhow, here it is:

To reset Grom-car Bluetooth: With radio on CD changer/Grom mode, change to FM mode and back into CD changer/Grom mode right away.
Wait about 2-3 seconds and then press SCAN button on radio (some stereos might be REPEAT button).
You should hear 2 beeps from the car speakers (might be low in volume), if your phone was connected to bluetooth it should disconnect.
If you do not hear the beep, please go back to FM mode, then switch back to Cd changer and press SCAN (or REPEAT) 2 to 4 times again within 3 seconds.
Hearing the low beep or the phone disconnect will verify that the Bluetooth has been reset.

Wait about 20 seconds, if phone was previously paired to bluetooth, you have to delete old Grom-Car from phone for it to pop up with new pin.
Delete old Grom-Car from phone, a new grom-car should pop up after the reset. Repair phone with the new grom-car.