First thing that comes to my mind when talking about what creates the "wow effect" is the ambient lighting. And especially Mercedes' ambient lighting. I mean, how can you not love that? The whole cockpit turns into a spaceship-like light fest with 64 (or something like that) different colors and combinations that match the driver's mindset and driving style. As an example, when driving home after a stressful day at work, the light blue ambient lighting calms you down. When driving your favorite twisty roads on a Friday, the lighting turns aggressively red and matches the sporty driving style.
Of course, this kind of exaggerated style doesn't fit every car and there are very different styles to execute it. Such as Volvo's very subtle light spots on the roof with only five or so colors with a sole purpose of bringing a certain luxurious feeling to the passengers.
The second, third and the fourth features are big screens, big screens and big screens. Buttons on pretty much anywhere else other than the steering wheel - and maybe on the center console - are just old fashioned, and will most likely kill that"wow" immediately. (Provided that they are not design elements themselves).
Big screens and more precisely, having nothing but big screens, were one of the reasons why Tesla received so much hype around their cars. Removing almost every button had never been properly done before.
Touchscreens are a preference thing. Some like it, but some say they only make the screens look dirty and prefer using buttons and touchpads to control what happens on the screens.
Personally, I think Mercedes has succeeded with finding the perfect balance between buttons, screens and other elements in their cockpits. In addition, the screens are touchscreens, but they can also be used with a touchpad placed on the center-console. Many car buyers, especially the young, are looking for a smartphone-like experience and buttons just aren't that.
It doesn't matter how big the screens are, if the UI (User Interface) is bad. And that's usually the hard part. The UI - or the HMI (Human Machine Interface) - is in a way the car's soul, and the only thing that communicates with the user. Therefore, it obviously must be user-friendly. But what does that mean?
The UI must look good, be specially designed to work seamlessly with each car model's controls, match the car's style and make the user feel like they know what they are doing, even if they are using the system for the first time. However, it still must be immersive enough, so the user doesn't get bored when he has owned the car for a while.
UI is a huge part of UX (user experience). UX is a combination of many things, not just the things that happen on the screens. It's how you control them, the lighting, the sounds and the atmosphere in the car.
These three features together, maybe combined with good stereo systems and comfortable seats, create a driving experience that is so close to perfect that the driver doesn't want to leave the car.
Because of all this, I think companies like Siili Auto are essential to the car manufacturers. The UI and the design choices connected to it like screens and ambient lighting are huge factors in creating the "wow" factor. If there weren't companies like them designing the UIs, I think our cars would be a lot more boring. It's amazing what the car UIs can do today, and how great they look. There are even more features coming up with voice and gesture commands developing every year.
To sum it up, I think the best UI is the kind, where you really don't have to pay attention to it at all.