Not to be contrarian, but here’s the thing. Having driven cars state-wide with 200, 300, 500K miles on them, I’ve had a few issues on the road. The problems are no longer major engine or transmission failure due to modern manufacturing, but things like sensors (crank, cam, MAF) idler pulleys, leaky water pumps, alternator failures, and so on. I always tried to do preventative repairs so that I would replace wear items before failure because I didn’t want to be 100 miles from home with a car problem. There’s no reason to expect a car with 150K on it to have an engine blow up on a long trip, which is relatively easy on a car, but you can certainly have a sensor failure, a wheel bearing failure, a fuel pump failure, an alternator failure, and so on.
With luck, the failures will happen at a convenient place and near a helpful mechanic. Without luck it’ll be 11:00 at night, pouring rain or snow, and in the middle of nowhere. More than once I made the call to the motor club for service on my son’s car a couple hundred miles away or drove the 90 miles for a repair. Stuff happens, and the older the car, the more likely something will happen. You can’t preemptively replace every dang wear part in anticipation or you might as well buy a new car.
So really knowing nothing about the car except a worried dad, its a crap shoot and maybe time for a new car. My main point is that good maintenance will not prevent a problem on the road. When my son was heading to school 200 miles away, I was relieved when he decided to give me back my Riviera and buy a newer car. Just sayin’ is all. Its a lonely road, people don’t stop to help anymore, and lots of women now carry weapons for protection.