Once official we'll know for sure. That said, though I don't like if the chassis sharering is true, Chrysler is better than VAG when they are to hide the donor chassis. Just look how exactly the same the Touareg and Cayenne are, almost rebadging. Same goes for Q5 and Macan and we'll see even more in the next years. The Chrysler 300C already shares with the Lancia Thema, 100 % rebadging. It is impossible for the Quattroporte to be based on the Chrysler. Just look at the weight of the Lancia Thema V6, it weighs over 2.000 kg. The Quattroporte is already not lightweight, and Maserati know that they have to reduce that weight, what is not possible on the 300C platform. The next Maserati Coupé/Cabrio will like the current ones be based on a shortened Quattroporte platform; I don't think the 300C/Thema will be turned into a coupé/cabrio. The Maserati that could get the 300 C platform would be the entry level Ghilbi, then sharing with the 300C, Thema and 166 successor. I guess why they come that early is because the platform is there. As for the Quattroporte, it is quite some time they are working on it, if I remember correctly, before the 300 C and Thema came out.