Air vents blowing too warm when AC is off

[spookybathtub]

Hi everyone.
I recently bought a 2007 Hatchback Yaris. I try to avoid using the AC whenever possible, to boost fuel economy. One really annoying thing I have noticed is that when the AC is off, the air from the vents is always much warmer than the outside air. I live in beautiful southern California, so summer evenings are commonly 60 - 65 degrees (F). But the air from my vents is uncomfortably warm - probably around 80 but I haven't actually measured it.

I know this makes sense, because the air is passing through the hot engine compartment, but it just seems more extreme than any other car I've driven. Does anybody else notice this, and has anyone come up with a solution?

Of course I could just open the windows, but I prefer having them up for audio reasons.