I’ve found that leaving a few windows cracked is more effective than the shades, but doing both certainly can’t hurt.
Except that I get rain where I live, so leaving windows cracked can be a bit of a gamble sometimes and I have to stay alert.
I used to have these little visor things that covered the top few inches of the side windows, that helped a lot because I live somewhere where it can suddenly rain.
You know, I’ve seen those on cars occasionally but it never actually twigged until now what they were for. I’m one of today’s lucky ten thousand. I’m going to see if I can find a set of those.