You are comparing premium tesla sedans with ford and Honda cars, of course premium car will take longer to build. Porsche for example produced 189,000 cars [1] in 2014 with 19,000 employees. And the average price of Porsche car is also lower than Tesla's.
[1] - http://press.porsche.com/news/release.php?id=897
The premium car will have lot more parts, like 26-speaker sound system etc, additional soundproofing, double-pane glass, heated _and_cooled seats etc. That takes work to install.
Next, the QA on a premium car has to me more stringent, simply because the expectations are higher.
So I can't imagine luxury car not taking more time to make than a budget car.
By which accounts? I've honestly never heard anyone complaining about QA or "Not Premium Enough"
For example, Top Speed suggests that all other manufacturers are still playing catch-up. That it'd be nice if the seats had been updated a bit, but otherwise things are great.
Buyers of premium cars expect details that are expensive to manufacture. That doesn't necessarily mean that it has to be difficult to manufacture them or that the productivity has to be low.
but tesla's production rate is increasing. the end of q2 saw rates of over 2k cars/week, which would be on target for >100k/year, over twice 2015's rate.
