I think you will find most of the times, the success lies in "Sniping"
If you are putting along with 80 km/h in 4th or 5th gear in your 3.2/GTA (cause it makes sense) and an innocent looking Skoda pulls up behind you, and then all of a sudden makes a quick ovetake then yes, it will seem quicker then the GTA. By the time you have reacted and geared down, it will be well passed you.
However, and take this from me. I also goes the other way round! In my innocent looking 156 3.2, i've sniped quite a few Diesels the same way. And by the time they react, the superior V6 power leaves them in the dust.
Nearly every day during the daily commute on the motorway, I will be doing the legal 110 km/h in the outer lane, overtaking trucks (double lane motorway) or trailers etc.. when some sales person in his 2.2 TDI estate whatever company car, comes racing up from behind doing 160-170 km/h and proceeds to tailgate me while i am overtaking the slower traffic(doing their legal 90 km/h). So i just drop the spped to 100, slip into 3rd gear and then it's byebye Diesel!
I usually raise the foot again at about 180-190 km/h, but by then they will be 100-150 meter behind me. Funny enough they dont seem so eager to pass me after that.
Part of my communte has been a 20km long straight single lane highway with oncomming traffic. Believe it or not, a lot of the Diesel drivers actually hit the accelerator if they notice i am trying to pass them.. It is quite sick! I dont know if this is a Danish thing only, but that sort of thing can really **** me off! It is really really dangerous, and it is also highly illegal here. They just passed a law which can suspend the license for this trick, and even result in a Jail sentence.
Anyway, in the past 6 moths, i have yet to meet any non BMW/Audi/Merc Diesel who can keep up with the 3.2 from 80-110 km/h as long as it is in the right gear. I am sure they are out there, but so far no Citroen, Peuget, VW or Jap mobile have managed.
I have also found that Diesels try to dominate the GTA more then the 156 Sleeper. Only problem they have, is that with 350 bhp from the supercharger they soon get into trouble
The GTA is so obvious though.. It looks fast, and the Rosso color just underlines it, and provokes certain people to try and dominate.
It is much more fun in the 3.2 sleeper.