I think the difference is that Turd Party refuse to pay licensing and so just do whatever they want. HasTak would happily pay the licence if Porsche just allowed it. Same with VW, and as soon as VW relented then VW Bumblebee was back in town!

Although I've noticed that VW has only been used for Bumblebee since the licence was acquired - notice that Gens Select Bug Bite, despite the name and original Machine Men character, is not a VW Beetle. I wonder if this is because one of the conditions of the licensing is that the VW can only be used on heroic characters. We know that VW and Porsche don't want their vehicles to be affiliated with war, it's not even Transformers, just not war. Because before the licence was acquired for Bumblebee, we know that Takara got away with using the VW Beetle on the Disney Label Donald Duck Transformer, because Disney Label TFs isn't seen as being "affiliated with war" - it's not classified as being part of the "main" Transformers toy line.

If Porsche similarly agrees to come to the table as VW did, I would expect that heroic characters like Jazz, Cliffjumper, Hubcap, Tailspin, Backstreet etc. would be allowed to be made with the Porsche licence, however "evil" characters like Dead End, Skystalker, Metrobomb etc. may not. Which dashes my hopes for a Masterpiece Metrobomb.