I recall when apple made the first iPhones, people said it wasn't possible to sell a phone with one button only. Tesla has designed a clean, efficient interface to match the internal and external decor. If you want additional buttons, I suspect you could glue or stitch them on and twirl them to your heart's content.
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Bman,
Almost forgot to tell you about the coolest feature of the car yet. I know I'm not supposed to say this to the non-owners (we've been sworn to secrecy). But, here goes. About a month into ownership, the car does a mind meld with you. It will just know when you want things to turn on/off. You think it and it just happens. I think that's the real reason behind the minimalist design. Honestly, the car just knows if your butt is cold, it turns on the seat heaters. If your kids are board in the back, it just flicks the windows up and down randomly. It's quite amazing. You should get one and see.