Thanks, 180... I'll pull the carpet up and have a look tomorrow afternoon.

I did connect my obd II reader to the Crossfire, and it only showed one code: P0600

Started the car and drove it up the street, first the low brake pad light came on, then all the other lights and the wing came up, with the switch blinking. It's a bit different each time.

I'll do a site search and see if there's a common fix. Everytime I find a good, similar thread, it ends with someone else saying "Did you ever find a solution to the problem?".