Well Alfa Romeo has only 1% of the production so it is for now nothing more than a blip on the radar. However, things can change quickly. It wasn't long ago that Porsche was a small sports car maker but now it is closing in on Cadillac.
First, the figures below which need three zeros to be added. Most of them are production numbers but some are sales figures, which are always close anyway. The data excludes commercial vehicles which would affect Mercedes mainly and Land Rover slightly. A small quantity of vehicles were made by Land Rover in China which is not included in the LR figure so the data here is just the UK amount.
The number after the production figure is the percentage of the total. For example, in 2014 the BMW Group made 2,161,000 cars and achieved 26% of all premium volume.
The four German car makers (not including MINI) took 68% of the total in 2014, up from 66% in 2010. Will they continue to grow in their share? I think they will be doing well to hold what they have. That is because the competition is fighting back. Other car makers are keen to tap into the bigger profits premium vehicles offer and are upping their game.
The three Japanese companies have nearly 12% in 2014, just a tad higher higher than 2010. Lexus and Infiniti are both determined to do better although I get the impression Acura is not high in Honda's priorities for expansion for the time being.
Volvo, and JLR were once under Ford's control but both now have Asian owners. Including MINI production went from nearly 15% in 2010 to just over 15% in 2014, which shows they are doing fine. MINI is probably somewhere near its maximum but the other have growth potential. Jaguar in particular will be strongly increasing over the next year or two.
The U.S. has two offerings, both neglected and without much international coverage. They were just over 5% in 2010 and are now down to 4.5%. GM seems to want to do more with Cadillac but Ford's ambitions with Lincoln appear to exclude reaching out to more markets.
That leaves the defunct Saab and the brand Mr Stadler doesn't know about, Alfa Romeo. Hopefully Saab will be allowed to rest peacefully. Alfa is still alive although on life support. If FCA can carry out even half of what it hopes, then Audi will notice.
Summary: There is much potential for premium cars as sales just keep rising, less affected by economic crashes and offering more generous profit margins. Everyone seemed to let the German makes get the jump on them but they will be coming back. Not enough to do much damage but enough to increase their share. They offer something different and the premium market needs that.