this was something i was going to do to my old gsi, but never got round to it so not sure if it works - i might miss something really obvious..
Go and buy off ebay.de or f.a.o any members on here off the continent a left-hand-drive nova rear tailight drivers' side - so your uk model has a matching pair of rear fog lights and no reverse light basically. Don't need reverse lights for mot...
Splice some new wiring into the top/stop and tail live wire on both lights and join the other part of the new wiring into the fog light position on both lights. Change the 21w fog light bulbs for 5w/21w stop and tail bulbs and.. hey presto a) You got better looking matching lights (simply tint the amber indicators red for an all red-euro look, or black or leave as is) and b) When u switch ur sidelights on and/or brake u get x4 lights come on - gotta look better than 2?!
btw- can't photoshop 'lights on' well i can't.. so cannot get an idea of what that'd look like. If anyone wants a lil wiring diagram, no prob - ill draw one up.