The dealer experience is pretty darn good.
I took delivery on a new Porsche. The transmission had a problem. So they flew a new one in from Germany by Fedex at a cost of perhaps $8,000 (after all it's pretty heavy) in air freight I was told. Loaner cars? Last time they gave me a brand new Cayman (I own a 911) with 300 miles on it. Other times Cayene Hybrids with 3k miles.
It's not without it's bumps of course (routine service maintenance was $450 to keep up the warranty Mercedes does something similar). But if you can't afford that type of thing you don't buy this type of car (at least not a new one).
The standards are higher for several reasons. One is that people with money don't take shit generally and are very demanding. So they keep the people working there in line and don't take bs answers and complain so much.
I brought the car in to fix a problem and when I was driving down 95 the repair broke. I called them they towed the car back and got the repair mechanic back from home (he had left for the day) and fixed it while I waited. I felt bad for him he was literally fearing for losing his job.