Where is this 200k cars coming from? I don't think there are nearly that many people who are willing to spend 50k (at the low end I think) for a car that would also choose a "brand" over the actual functionality of the car. Tesla has it, but they weren't a brand associated with other products first. They where all "car snob" from the beginning (which is fine). And i just can't imagine Apple making a car (likely a 4 door sedan) that beats the Mercedes, Audie's, Lexus's, ect in functionality around 50k. Sorry, I just don't see that many people that could afford it and would choose and "icar" over a Jaguar XF for instance.
Well, Musk didn't know crap about cars or even manufacturing until he started, and even though he's rich, he's not even close to having the kind money they have to develop this. He ran into financial issues. Its not even in the same ballpark. So, they could side step a lot of his difficulties by poaching top level engineers left and right and buying companies with lots of IP.
Very few make electric cars. The key to them is battery tech. It is a brand new field were incumbent don't have a major advantage on up and comers with money. In that, it looks a lot like the smart phone industry in 2006.
BTW, Apple also could even easily buy controlling interest in BMV and still have more than 130B cash to play with.
As for the 10B. Its coming from my own what if numbers. If you do 10B in revenues your in the top 30 car makers in the world right now. Most top 30 makers right now are profitable. They don't have to shoot for the moon to make a good profit. IF the average price per car is 40K (a bit less than the average selling price of a Lexus) that's 250K cars. (that's about 60% of the numbers Volvo ship).
If you look at most high end makers I listed, their low end cars are usually in the 35-40K range. 35-40K is usually the high end price of the normal car range too (say the Nissan's Maxima). That's the crossover point it seems.
Selling cars direct (bypassing dealers) and adding electronic flourishes, Apple could boost the usual net margins. We got(10-13% high end margins) + (half the normal dealer margin (3-4%)) + (whatever markeup for Apple's specific tech (say 5-8%)) = 18-25% as a potential net margin.
That's for normal cars. But, electric cars are simpler beasts from a manufacturing point of view (but not the R&D point of view), were battery cost accounts for a big chunk of the current cost. IF you controlled the battery tech and the electronics. You could significantly boost your margins. That's what Tesla is attempting; but battery development is risky and expensive. That's an area were Apple's financial clout would give it a big leg up.
The Apple "brand" car would have al the functionality of others cars, plus whatever Apple adds. Not sure why you think it would have less functionality than all other cars if it ever exists. The reason people trust a brand is because there are actual implied guarantee of some level of quality/service/experience/cachet behind it. They don't do it only for marketing reason (Apple spends less on marketing per revenues than its competition anyway).