If I want to press the fourth button from the left while driving - with a tactile button I can reach, count over the three buttons as my finger slides across them, and press the fourth button. Without removing my eyes from the road.

With touch buttons I need to look at the screen which takes my eyes off the road. Even if it's for 1/2 a second.

1/2 a second is the cause of many accidents. I'd prefer having physical buttons. Ironically, you lose your sense of touch on a touch screen.

I understand the objections. I just don't find them to actually apply in the real world.

First, what functions do you actually need to manipulate while driving? Most of that can be done from the steering wheel.

Second, when positions on a touchscreen are consistent you can learn to touch them without staring at them. I often adjust the interior temperature on the touchscreen even though it can be done on the steering wheel, just because I find it to be easier. It can be done out of the corner of my eye with practice.

Counting buttons is no less distracting than a quick glance away from the road. If you don't have time to glance at a screen, you shouldn't be messing with physical buttons either.

The trouble starts when the UI is designed poorly enough to require more than just a glance.