A friend has a '69 Stingray and is computer challenged, so I told him I'd try to find an answer for him. His car starts up fine the first couple of starts of the day and then gets progressively harder to start as the day continues. We live in LA (Lower Alabama)and it is hot here. He says that the battery is fine and wonders if it is the starter wearing out. I believe it is an all stock car, no engine mods, etc. I've seen a heat shield sold in Summit to prevent or reduce "heat soaking". What is heat soaking and could this be the problem on my friends Vette? Any help would be much appreciated.