I wonder how much the higher end names are even involved with the car audio systems design and manufacturing. I bet many of them are simply putting their name on a ordinary system manufactured by a no name or non premium reputation manufacturer.
Car makers do that all the time. Rebadging - Toyota to Lexus, Honda to Acura, Nissan to Infinit, etc. How much of the premium is name only, and how much is actually reflected in their parts and manufacturing cost. If you subtract out the increased advertising expenditure, I bet it is not a great deal. But it sells - snob appeal costs money.