I am an auto electrician ;)

Still can fit a socket where there isnt space for one though...lol

Before attempting. THIS WILL VOID WARRANTY FOR SURE AND SO WILL ANY OTHER TAMPERING WITH ELECTRICS. YES EVEN CHANGING WATTAGE OF BULB WILL VOID WARRANTY DUE TO EXTRA HEAT EMITTED.

There is the same ammount of space as the other cluster where one is fitted. Just take off the cluster, drill a hole (the size of the socket thread) in the same place as on the other cluster. Insert socket from inside cluster (or outside depending on individual design). Screw on rear of socket (or front if as before design is other way round). Wire it up (you should know how to do the last bit).

See socket below. Available from any hardware store.

P.s. Don't forget to seal it.

FZ4D1XUFGBQ3VBS.MEDIUM.jpg
 
Before anyone comes with some form of smart reply, I know it is too big and I am not suggesting you fit a regular bulb. It is the ony pic I could find of the type I was looking.
 
is there a reflector and a gap in there for it though ? the lens appears to suggest it's not as simple as it appears
 
Same space and reflector on both clusters with a "fake" bulb (put there to make the rear look symetrical) that you need to remove to do the job.
 
Just so nobody gets confused I am talking about the reversing light. There is no reflector for the missing rear fog light. I'm guessing it is because the reverse light is clear and the rear fog is not (red so you can't really see inside unless you look at it close up).
 
I had my first 'you have faulty fog lights' moment this morning. I explained how they work and that was fine but then I was told both fogs came on when I reversed - I couldn't explain the logic of this though. Can anyone help me out?