VAG paint is solid... as you have found a combo that works well on one car is useless on another... thats what makes this detailing malarky something that takes time to perfect
I recently did an Audi A6 Avant and a polishing pad with Meguiars 105 compound (high cut) did nothing. 2 passes with the same product on a cutting pad gave the results i was after but left loads of holograming as that compound will not break down enough to give a LSP ready finish.
I followed it up with a pass of Meguiars 205 on a polishing pad and the results were spot on.
Chemical Guys Hex Logic pads are good, they seem to work really well with every compound i have. Meguiars and 3M pads are also very good and i use a lot of them. 3M pads are my favourite for applying cleansers or glazes by machine as they are generally a bit softer than other makes.