Drove today from Daytona to West Palm taking the back roads so I was in the sun for about 4 hours. It was about 85 degrees and sunny. The interior stayed in the mid 70's and the vent temperature was about 45-51 degrees.
I did the Vipers mods (minus all the interior cabin insulation he did, and have untinted windows) and I also did the Tony Wa heater bypass which keeps the vent temperature down a few degrees also.
I actaully had to shut the a/c off since it was getting too cold, since the bypass does not let you raise the temperature.