Mercedes-Benz sold 2.31 million passenger cars last year, likely enough to make it the top-selling premium automotive brand in 2018, although some analysts are questioning how much longer German manufacturers can dominate the luxury car industry.
"The question is whether Tesla is the Apple
The success of the German manufacturers is based on sales of combustion engined vehicles at a time when customers are hankering for newer electric cars with sophisticated software-based infotainment systems.
The Germans are also launching electric cars, but their profits come mainly from sales of high-horsepower diesel and petrol engined vehicles.
Mercedes-Benz posted a new sales record last year thanks to an 11 percent sales jump in China, the world's largest car market, while sales in the United States and Europe fell 6.3 percent and 2.3 percent respectively.
Its flagship S-class saloon saw sales rise 12 percent, while more than a third of customers chose to buy a sport-utility vehicle (SUV), and around 25 percent of sales were compact cars, Mercedes-Benz said.
BMW will release annual sales figures for BMW-branded passenger cars on Friday. BMW Group, which includes the Mini and Rolls-Royce brands, sold 2.49 million cars last year.
By contrast, Mercedes-Benz and its sister brand Smart sold 2.44 million cars last year.
Hummel said Tesla could pose a threat in the medium term because it offers better connectivity and over-the-air updates.
"Tesla has a lead of three to four years in areas like software and electronics. The millennials are much more focused on these things. There is a risk that the Germans can't catch up," he said.