I just deal with the heat.
I take my shirt off if it gets too hot. Having a white car with a light interior definitely helps, as does having an all windows down feature using the key fob. Lower all the windows as you are walking up to the car, it makes getting in after sitting in the sun much more bearable.
Something interesting I saw recently was pretty much a dashboard carpet, lightly colored I imagine it could reduce interior heat quite a bit. It just has to be sized correctly as to not block any airbags.