I like that idea. I'd seen that but it is sort of difficult to try out and remove if you don't like it. But I like the way it looks.
Here's something I tried with the iPad. Under the General settings, go to accessibility and enable the zoom feature. Then, use three fingers to double tap and set it up as you like. In this case, I put 6 icons on the screen.
If you set the first 6 icons on each page to your car apps, you can page through them king-sized. Triple tapping will zoom everything back to normal if you need to operate the controls for some reason.
It's not perfect, but it is *bigger*.
Still, I'd agree about the need for a front end app of some type.