Had a similar issue with my twin door superb. Dash displaying a left reverse bulb out but when replaced the bulb indicator was still lit on the dash. As per paddymallon's post above, i removed the trim on the boot I disconnected the plugs and pulled the loom backwards towards the roof and found that there was a small blue wire broken just where the saloon boot opens from the twin door on the left side. A few more wires had stress damage from the boot opening and closing in saloon mode . . Used some extra wire to extend the wires. Soldered and used shrink tube and rewapped the loom. Solved the issue for me. So I'd like to confirm that this is indeed a fix if you have a bulb indicator on dash related to rear lights but bulbs ok.
