And historically when the Japanese _have_ gone overboard on tech, back in the bubble era, they also tend to back it up with overengineering.
Think of the fourth-gen Toyota Supra or any version of the Nissan Skyline GT-R. Or the Toyota Soarer/Lexus SC, which was basically a detuned Supra packed with luxury equipment and unique styling. They were technological marvels whose engines were overengineered beasts that could take ridiculous amounts of abuse.
At one point when my father was restoring a Mk 3 Supra, I got a look at the traction control boards since he had pulled one out to fix it. I was surprised at the lack of surface mount components, only to have my father point out the board had been made in 1989...
The Supra was a fundamentally ahead of its time design. Not without flaws but definitely pushing into new territory.
Maybe I misunderstand what you meant - but there were SMT components in 1989; indeed, some of the earliest examples of SMT can be found far earlier (late 1960s for example).
The reason it was likely thru-hole construction probably had more to do with reliability, as SMT work is more prone to damage from vibration (mainly), unless properly potted or conformal coated (and there may have been issues as to why they couldn't do that, either).
That said, consumer-level use of SMT components didn't really start until the early 1990s - but examples of earlier use do exist (for instance, one of my floppy drives off my first computer in 1986-ish had SMT components on the controller board - but it was still mostly thru-hole construction).
The 2JZ engine was one of the best (as in, most durable) engines that Toyota ever produced.
The sheer number of Supras, Lexus IS300s (1st generation), and GS300s that are still running today, most with over 200k miles, is a testament to the amount of over-engineering that went into that engine.
And then there are the crazies who took the NA version and added turbos...
A lot of E46 M3s are still running around with 200k on the clock despite having motors and chassis that chew themselves up. Same with the MK3 Supra and its headgaskets. IMO whether you still see cars around is as much a function of their value retention as it is of their robustness.
German cars tend to be over-engineered; lots of modern tech in the vehicle + manufacturing, whereas American cars tend to be quite the opposite.