why not just get into your attic and properly insulate it? Keep it at 1 temp and be done.
or you could insulate your attic get a programmable thermostat and have a win win.
the built auto's are actually pretty reliable, to launch you have a spray, so its the motor and t-case you have to worry about.
this can be done on a stock auto with a progressive controller (both boost and nitrous)
i like driving little trucks
http://www.thecarcompanyonline.com/show_image.php?file=/home/ebaitbiz/public_html/ebait_images/cc0n71ne/2005-Ford-Super-Duty-F-350-DRW_C61437-1.jpg&curw=640&curh=480&width=640