The electronics can be an issue, especially if you happen to get a car with an abundance of gremlins roaming around in the wiring. That being said, I have had very little to no issues with electronics in my cars. Older cars are, without a doubt, easier to diagnose and subsequently repair due to their simplistic nature than their successors. As far as drive by wire systems, aircraft have had fly by wire for years. Airbus went through some teething troubles with their system early in the life cycle, most notably the Air France flight 296. That being said, there are millions of flying hours completed every year with fly by wire systems.
I have seriously considered purchasing a classic muscle car, but the overall lack of safety in the older cars keeps coming up in my mind when I start thinking about doing such a silly thing. The survivability of a new car in a crash is substantially better than older vehicles. After a severe car crash in 1985, that is a consideration for me.
Back on track, there are nearly no new vehicles around here at all. Dealers are consolidating their lots and downsizing. Literally last night I was poking around the internet for a new Ram truck. There were NONE configured even close to what I was looking for.