They’re actually not bad for space! I’m about 1.9m / 6’3", and while I’m not that heavily-built I’m definitely not unusually slim. It wasn’t roomy for sure, but I fit just fine. The lack of a roof did at least mean that headroom wasn’t a concern

I did once have to back out of a purchase of a second gen Toyota MR2 because I was too tall. That was a deeply disappointing day