As I learn more and more about different cars, I'm fairly convinced there isn't a car model available without it's own set of troubles and problems.
I know about quite a few of the issues of BMW's past and present. A few of my friends track only BMW's with no troubles ever, some with significant mileage and track time. My brother has a 2013 328i he bought new that has never needed a repair beyond a software update for the I-drive. If I were to grab from just that limited sample set (which is what most people do), I'd say they were fantastically reliable.
But I also have track buddies that have newer M3's that need rod bearing PM, VANOS issues, and a friend that had a X3 with a transmission that seemed made of glass.
But it's no different than problems with various late models of Audio, Porsche, Ford, Subaru, VW, Toyota, etc. I could go on all night about the issues with Corvettes.
I think the Supra will be fine.