VW AG's great strength is they can leverage their wealth of brands such that the staggering costs of R&D (the A5 platform which underpins the Mk5/6 Golf, A3, Leon etc cost 0.5B euro) can be amortized across a whole range of cars, enabling companies like Skoda and Seat to put out highly competitive well-equipped vehicles at a very reasonable cost which they would not be able to do otherwise. Ford is doing the same thing with the new Focus platform, which is not only behind the new "Global Focus", but also in thirteen other vehicles. The problem is of course product differentiation, and this is where GM failed, and which VW is in danger of (because how different is a high spec Golf from an A3 these days?).