I junked the standard rear lights, along with quite a few other bits
I have a simple LED back light unit from Motrax (I think) ... £22 from local bike shop. It's about 120mm long, 30mm wide and is oval in shape.
Will try to include a decent pic if I can find one. (found one)
[Edited on 18-8-2005 by Carbon749]
[Edited on 18-8-2005 by Carbon749]