Mercedes-Benz's 3-pointed star stands for Land-Air-Sea.
Mercedes got that star from a postcard Gotlieb Damlier wrote to his wife in which he drew the star atop a house and said that one day a similar star would hang above his factory to symbolize prosperity. His sons adopted it and actually registered two designs, a 3 pointed star and a 4 pointed one. Only the 3 pointed one was ever used. When the company merged with Benz, the star was wrapped in benz's laurel crest logo, creating an early version of the circled star we know today
Or how the MB employee said, I start work at 7 am, lunch break at 12 and leave at 5pm.