Not sure where you got those relatively high margin numbers. The low end in your numbers are the actual high end in the automotive industry. Take higher end car companies BMW, Audi, and Mercedes. For 2013, BMW's net margin was 10.5, Audi was 10.1, and Mercedes was 6.5. Cursory search didn't reveal the full year 2014 numbers.
Gross margins?
BMW 5yr avg 20%. High of 24 and low of 13.5
Mercedes avg 22%. High of 25 low of 20
Audi is in the VW numbers. Average 18%. High of 19.4 and low of 15.1
For perspective the net margins at the big three are 3.9 for Ford, 4.1 for GM, and 4.5 for Chrysler. Apple's net? 22%. Apple is next level when it comes to profits and margin; both gross and net. The car industry really has no place for next level. There's a big difference in the financial outlay from the consumer of an electronic device and a consumer of an automobile.