I had a '07 BMW E92 335 coupe. It did not have rear fog lights. However, somebody at E90post forums has found out that the rear fog lights and even the button to turn them on was there but the button was disabled by BMW for NA cars. Tons of post members took the light control mechanism out, detached the piece that turns on the fog lights from the mechanism and put everything back together. That was it - you have working fog lights which you can turn on and off.

I'm curious if it's same with E70s.