This entire "texting while driving " argument is inane. The OP is complaining when, if he doesn't like it, he should've driven himself. Simple as that. For someone who got to sit in a back seat and put his feet up while someone else carted his ass back and forth, he has NO room to complain.
I don't know, what if the dude was putting away a six-pack while he was driving? Still no room to complain? Not that those are necessarily equal in risk, but if someone's driving makes me uncomfortable I'm going to at least say something. If they tell me to **** off then I figure they're not much of a friend and I'll make a different decision next time. I'd much rather drive myself; somehow, even with ADHD I can manage to drive 10+ hours in a row without having to keep myself entertained by playing with my phone.