Originally Posted by dieseldiehard

Gearbox is not the problem.
I believe the turbo boost is involved with a problem that has to do with built up boost, suddenly you want the engine rpm dropping so you can shift gears so you have to dump the pressure than you want it back when you hit the accelerator pedal but it takes time to spool up the turbo to get back into the power band, you know that sort of thing probably goes against the fine German engineering thought process. If they had figured out how to make the system work fine with a turbo behind a stick shift I believe there would be lots of them (here and in Germany!)
There were at least two turbos with sticks trannys here in the Bay Area, Ben Ridge for one until he moved to Oregon (do a search for Ridge). He claimed it was like a marriage made in heaven. The other individual was a pilot, he had a 300D turbo/stick combo for sale. I am certain he developed a method for shifting that an airplane pilot would have perfected. I never drove it unfortunately before he sold it. Its surely OK for a gear head, but don't give that car to a parking valet!