I live in South Texas and can tell you that window tinting does indeed help.

The most savings come not from allowing more frequent auto-stops (I found that the car will still warm up almost immediately and require a restart), but from the fact that you can set the A/C temp a little higher to achieve the same degree of relative comfort.... which means that your A/C compressor turns-on for a shorter period of time, putting less drag on the engine.

Additionally after a full day in a parking lot, the vehicle's interior feels less warm, meaning that you'll get to your comfort zone a little faster.

The U.S. has reached a point “where the priorities of Congress could become so distorted by politics” that it would turn its back on the next great global industry, clean power — Rhone Resch