Yeah convertibles don't really work in the summer aside from when the sun goes down. Ace in So-Cal in winter though. That said, we've had two and haven't troubled the canvas with much regularity.
My mum permanently had the roof down on her mx5 in the summer in France. The problem comes when you're stuff in gridlocked traffic on a freeway, rarely going fast enough to get the air in and outrun the pollution.
Yeah convertibles don't really work in the summer aside from when the sun goes down. Ace in So-Cal in winter though. That said, we've had two and haven't troubled the canvas with much regularity.