Note that I'm not doubting you, more them ... lookit the Japanese for example, everything's grandpa's axe rather than fully new (current Mazda3 for example is mods-to-mods-to-mods-to the original Mazda3 that replaced the 323, despite it being the 4th generation). Same with Toyota. Same with VW come to think of it.
Having typed that, I don't remember enough about what VW or Toyota were up to in terms of platforms in the (say) late 90's. Maybe each new generation was a brand new design, in the main? Subaru's been grandpa's-axing their entire range pretty much since they released their first car which didn't drive like a Hilux, the Legacy, in '87 ...