@the bolded bit: AHA! Finally my pet peeve about people calling Roadsters "Teslas" has a real world example! See how confusing that sentence reads?
It's fine for me.
But I see your point.
It's another catch 22. People who have never head of the car ask what is it? The answer at this point is. "It's a Tesla". Saying it's a Tesla Roadster is too much information, not pithy enough for quick memorization (the word itself is hard enough) Of course you can't say "Roadster" because you might as well say. "sports car" or Go Cart. it's too generic. It would not help spread the word even if they remembered it. You want them to have the company name as the takeaway.
So until there are two cars on the road -or nearly so- I will continue with the shorthand of "Tesla". I realize it is inaccurate and unspecific but the name Tesla must be spread and calling their flagship car by the comapny name for a while to help spread the word is a small price to pay.