I'm still very new to my Boxster and also getting used to it. Certainly on my UK Spec 2.7 Tiptronic, if you use the Tiptronics gear selectors on the steering wheel, you can see on your dashboard indicator that it changes from "D" to "M", then depending upon how hard you are driving, it changes up and switches back over to Automatic. If you move the gear-shift lever across into "M" out of "D", then you are "on your own" and as you describe pretty well, you end up having one of those "
Oh My God!!! moments all the way to the Red line.
