Late 90’s, Early 2000’s was a good time for reliable engineering, but it’s worth looking into owner groups for finding good reliable cars. Toyota, Honda, Mazda, Nissan, etc from the time was always likely to be a good choice, but still some are cheap to buy, expensive to own cars, and vice versa with the euro competitors. Many known for unreliability, but Audi, Alfa Romeo, Skoda, fiat, Opel and more, all had a few trusty and well built cars, as long as you can find a good owner history too and do the research
But that has been cars since forever. The Nissan 400z is just a 370z with some updates, the G3 Subaru imprezza moved their manufacturing to another plant and made them “wide body” but is the exact same, look up the MQB platform from Volkswagen and the list is endless. Same with engines, Volvo modular series of engines has been in production since early 90’s and still is to this day with a some changes, and again with Subaru and their EJ series of engines or GM with the infamous LS series. Putting a new body on a old chassis is just how it goes, because simply, it is cost effective, and if it works, why spend the billions in starting from scratch, put the money in a new designs and fix other issues