I think most of us do fairly well when the car is moving. I have the most trouble when it is really hot and I'm in stop and go traffic. I did a thorough cleaning of the radiator recently which really helped a lot. I haven't really been in such conditions again, though. It's in the 90s today, so I'll see what happens.
Does your car stay cool when you are just idling on a hot day?
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351W 89 Mustang GT Convertible