Check this link out and tell me if it's what you were inquiring about:

Benny\'s Xterra Rear Dome Mod

This is something I'm considering... I, too, am interested in a bit more illumination
from the back of the X... I'll probably "borrow" Benny's idea on the lighting...

Here's another link from Benny... This one is for additional backup lights...

Benny\'s Xterra Backup Lighting Mod

PEACE!!!

- Air B