The great thing about the minivans, they have a lot of good convenient stuff, have terrible resale value (good when you are buying) and probably get yo the most bang for the buck.
All modern cars are the most reliable in automotive history. If a vehicle can't get 200K, it is junk verses in the "good ol' days", 50K and you are giving them to your teenager, 100K they are going to the bone yard. Most, if decently maintained and I just mean change the oil every 5-10K and wash it a few times a year, will be decent. I think you are right about looking out for those cars that have a consistent issue. But I bet if you research, it is probably in the upper 100K region they start to have problems.
I have worked in manufacturing for over 40 years now, the precision, the techniques are so exact, so well designed, such an incredible feat of engineering and manufacturing technique is really a modern miracle.
I think you will be able to spot a turd, but look at the minivans, I think you will find some gems there. At least a good place to look.