I'm hoping some folks can relate to this and maybe supply an answer.
I live in Texas and travel regularly here, and in the South. I recently bought a small SUV for getting about with my guitars and a sound system - but I have a problem.

The Texas heat is murder on guitars and I don't always want to take my instrument into places I go when traveling in the hot weather. Question - is there something out there that I can cover my guitar with, or wrap my guitar in to keep the sun off of it and keep it from getting over-heated? Are there any hi-tech covers that would do the job from the camping or outdoor world? Surely I do not need to remind that my guitars are all in their cases, right? Any help or ideas would be welcome. Thanks.