Well, you shouldn't forget, that Manthey is their most supported Team or THEIR Worksteam. Just have a look at the 24H or VLN races: Mechanics, Drivers and even a lot of Engineers, which are working, are directly from Porsche. The RSR or the the GT3 R ran by Manthey are cars, which are supported with the best of the best development parts Porsche has. In that case, Manthey is way more a Worksteam than Flying Lizard or Felbermayer.
They are racing in GT Open, because Porsche wanted to do them and their yellow and green GT3 R is likely more developed than any other GT3 R around ;-) (This also was a important part on discussions in the 2010 VLN mid-season, when they had a look how much power this GT3 R really has and when the Split Mamerow/ Porsche came around)
So due to that, i would not be surprised if Manthey would be part of ther 2013 GTE-Programm
