thank you for your question.
The answer is:
I cancelled the trip because
a) I did not get of from work during spring 2009
b) I did not have satisfying information on the entry regulations for a European registered vehicles (one of my options was to sell the car in Kurdish Irak)
And therefore I went to West Africa in the last winter instead.
The only information I gathered in 2008 was that some Germans had to deposit their passports at the border between Turkey and Iraq when they entered Kurdish Iraq with their mobile homes.
I got this piece of information of this website( sorry only in German):
Iran, Irak & Türkei 2008 – n48e11.de
I guess (but I do not know) that there is an other kind of regulation in place, since Kurdish Iraq has seen quite in inflow of tourists. Pleas post any recent Information you gathered regarding the question of entry regulations.