- might be a long shot Mike but on my Aero8, the foglight bulb is accessed from the rear (Oer Missus!).
All the other lamps have two screws at the front but this one has a large screw cap (almost like a jam jar lid) at the back of the lamp.Getting to it necessitates taking the boot box out- or it can be managed by bending the side back and slicing your hand to pieces!
I know the +4 is a different animal (i.e. no boot !) but it may be a similar (Morgan) set up....?
Hmm... good idea, perhaps lifting out the spare might give access? I'll take a look and report back!