My first pet peeve about modern cars is the "entertainment system" screen being super bright and not being able to make it completely dark with a single button hit.
I understand that they're super useful for backing up, and I'm fine with them existing because of that, but in my wife's car I have to go into setup, then some other mode, and finally hit "turn screen off" (of course, it comes right back on in some circumstances, which is fine, but what's not fine is that I have to go through a multi-button hit to darken it back again - of course requiring looking at the damn thing in the process).
Second is not being able to do heater/ac stuff without looking. My truck has three dials, and I don't even think about what to do, I feel a certain way and without thinking my hands adjust the temperature just so, and I'm left going "oh right, i was hot". Yeah I know automatic temperature-tracking ac/heating is neat and fancy but the truth is when I get in the car, I'm either too cold or too hot so I want a big dose of the opposite, and then I end up correcting it to the "right" temperature at some point. I should be able to do all of this while driving without my thought and definitely without taking my eyes off of the road.