Once I passed the age of 60 I decided that my days of crawling under vehicles were over. But I'll get out and wash both Jeeps when they need it. And I applied ceramic coating to both. Man, was that a chore.
I've taken my 2.0T on a couple of long (more than 1200 miles) road trips w/o even thinking about a cool down when I park it. I make regular 250 mile trips. Same - same.
Never had a hiccup.
I have the OEM headliner in my 2dr. I find it lowers road noise and no doubt helps with keeping the cabin a tad cooler.
And the summer Texas sun really heats things up after 10 am each morning.