Well, if Preuniger maintains the "N/A engines for GT car only" then it could only be the 4.0 L for the next GT4 generation...unless, Porsche is forced to come up with a detuned version for whatever race series other RT members may know more about, I cannot think of a next generation to come. At least IMO it seems that there is currently not such a high demand for used GT4s, although prices are still high up - and, there is no pressing need for Porsche to do something in this mid engine area. What I seem still certain about is that the used car market for GT4s in CH may be going through the roof, if and when in a few months time, a white GT4 may be up for sale...