Personally, I've never liked the spoiler on the back of the 107. It always looked like a low-rent after market item to me. I'm not so sure about the functional aspects either. M-B had sold a good few 107s before they introduced the spoiler and I don't believe that the car had gained a reputation for lift at speed.

As ever though, it's your car and your choice

--
bobw
1983 380SL
1991 BMW 735iSE