It seems these monsters benefit from an air dam it will reduce cdA by .02 and a rear spoiler will further reduce it by .015. Lowering the car knocks another .02 off so it's starting to look almost ok aero wise.
Well compared to the stock .4 cdA .345 isn't terrible when you look where it started.
Don't forget losing the mudflaps and putting those lower fog lights into your new air dam (or deleting them if you don't need em'). That's gotta be good for a little more aero.
How does a rear spoiler reduce drag? Is that part of the Kam idea? My understanding is that rear spoilers increase drag by providing down force. Am I wrong there?
On this car the spoiler doesn't rise off the decklid it just extends it out. I'm not sure how it improves aero (I guess it extends the bubble formed by the rear window turbulence). The info I have is from the BMW parts catalog vintage 1988 so who knows if any of it is true.