I'll I can say is when I lived in PHX Arizona they had a display in the video store showing a melted/distorted VCR tape with a big note saying do not leave tapes in your car (escpecially on the dash).
Consider the interior of your car as a hot oven on a hot sunny day. Your interior temperature can reach about 190+ degrees (depending on what part of the country you're in). All it takes for ABS to slightly warp is around 100 degrees.
I have personal, first hand knowledge that ABS warps in the car on a hot, sunny day.