I just reinstalled the carputer, and now when I turn off the car and remove the key, the airbag light comes and stays on, plus the usb hub (powered by the cig lighter) stays on but the radio doesn't stay on lol. Normally the cig lighter only comes on when the key is in ACC or ON. The cig lighter and airbag light will go off after 10 seconds after locking the car.

If I just turn the key to ON or ACC then turn it back to OFF and remove it, this doesn't happen. But if I start the car and then turn it off and remove the key this problem occurs.

When I turn on the car, the airbag light illuminates then goes off as usual and everything operates normally. Wondering if anyone had a similar problem? Hmm must do some more fault finding tomorrow.

I just had an idea, cos the pc stays on for 60 secs after I remove the key, it might be that the 5v from the pc usb is being fed back into the car's electrical system through the usb hub, into the regulator and into cig lighter. Then the airbag light is staying on as it's thinking the key is in ACC as there is voltage on the line but there isn't enough power for the self diagnosis to pass. Although this should really be impossible it seems it might be the problem, will have to check tomorrow.