Yes, I'm well aware of this. There are plenty of locations where that's not really a problem, though. And generally when they're hotter and therefore less efficient it means there's also relatively abundant sunlight, somewhat counteracting the effect of the heat. Cars also aren't necessarily that hot, particularly if they aren't powered by burning stuff. And putting all of that under the shade of a canopy would reduce the heat reaching the ground. If you used a brighter paving material like concrete, you could even benefit from bifacial panels using the reflected energy.

There are problems and there are solutions, maybe the problems outweigh the solutions but it's still a worthwhile avenue of research to find that out.