That would be a cool iPod (better than dealing with the non-buttons on my iPod Touch). The Model S is obviously a luxury vehicle in addition to being an electric car, and luxury pretty much equates to "cutting-edge, whether it's practical or not."
Marketability aside, I'd design an electric car to be as spartan as possible, maximizing range and minimizing unnecessary energy consumption. That makes the most sense to me.
It's a context thing though. The Model S is a car with, according to the EPA, up to 265 miles of range.
A touchscreen takes very little energy to power. More than there not being one at all, of course, but I think you're being a little harsh with the "whether it's practical or not" comment since that touchscreen allows users to plan where the next Supercharger quick-charge station is, for example. And being so large it also rather offsets the small missable buttons argument - when a full half of the screen can be dedicated to the climate control the usable area is about four times the size of your average grouping of HVAC knobs and switches.
Anyway, on energy consumption I'd imagine even a massive one like in the Model S isn't a particularly big draw, certainly not compared to something like the car's headlights or the heating system itself.
And then it all goes back to the "cutting-edge" thing, since I suspect most buyers would be a bit disappointed if they'd bought one of the most advanced cars on the road to find a selection of heating and radio knobs from some parts bin somewhere (probably Daimler, given the two companies' connection).
On the aesthetic thing, that's obviously personal preference. But to me they're really no less aesthetic than myriad little-used buttons filling the dashboard.
On the other hand, down the road, there are more electronics and things to go wrong than a range-topping BMW or Mercedes-Benz from yesteryear. Some '90s cars (and not just luxury cars) offer their owners enough headaches already. Fancy tech almost always becomes a liability.
I feel like this is a subject that's massively overplayed, too.
Yes, some electronic gadgets can be a pain in the arse. Buying anything French from the 90s and early 2000s with lots of toys is a nightmare. But then (much as I love French cars), cars from that country have never been particularly great on that sort of thing.
But let's look at it logically - cars with ECUs have been around for decades now. And how often does that ECU itself goes wrong? If an electronic injection car is doing something wrong it's typically the fault of physical objects somewhere in the fuel or ignition system (or simple, been-around-forever mechanical parts in the engine), rather than the electronic brain.
You can still buy a Mercedes from the 1980s whose electric windows sail up and down without issue. You can still buy a Lexus LS400 from 1990 in which every single interior feature works as it did when new. As I mentioned to someone else a few posts ago, the digital display in my Honda still works as it did when it left the factory. No dropped pixels or liquid crystal issues at 13 years old, and there's little reason that should change.
Essentially, if you pay for quality then you get quality back. An early Ford SYNC system will still be crap in 20 years because it's crap today. But the system in say, a modern Lexus GS, is no more likely to go wrong a few decades down the line than the car itself is.
So with respect, "Fancy tech almost always becomes a liability" sounds more like something someone who doesn't like fancy tech in the first place would say to justify its absence, than it is speaking from experience.
But just last weekend, I had a go with Honda's latest try. Honda is so confident in its new touchscreen controls that this car has no physical climate control buttons. Not even the "pretend" ones like on the Ford Explorer dashboard.
Peugeot's new 308 is the same. Has one rotating knob on the dash, and a few important buttons (hazard flashers, screen demist etc) for major functions, but everything else is contained within the touchscreen, with function submenus to the side - heating, radio, navigation etc.
Now apropos of my comments to Wolfe above concerning tech in French cars it remains to be seen how well it stands up to the passing of time, but in terms of functionality it's very good indeed. You can see the HVAC screen in the image above - big, obvious buttons that aren't at all difficult to use, and obviously tidy up the dashboard no end.
I still prefer more intuitively fuzzy dial-type controls, but some of these new systems aren't bad at all. If I had my way, all I'd ask for is at least six reconfigurable buttons/dials to allow you to access common commands with a single touch.
Honestly, this describes me too. I can understand the arguments of those who prefer physical buttons to touchscreens, but some of the modern touchscreens are far better than some here are giving them credit for. And far less "distracting" than people are making out.
Though again, I reckon in the average modern car, if you still wanted a simplistic look, you could get away with three, dual-function knobs. Imagined on the Peugeot dash above there'd be another two to sit alongside the offset knob on the dash, next to what looks like a CD slot but is actually just a styled metal strip. Anyway...
You have a button there that selects between HVAC and stereo controls. So depending on which of those is selected, the three knobs either do heat/fan speed/air direction, or volume/skip/tuner. Or something. Every other little-used function could be incorporated into a screen, which incidentally could show the current function so you're aware what the knobs are doing.
I think the Nissan Juke already has something fairly similar with its buttons. A switch selects between either HVAC or driving modes, and the buttons change accordingly.