I must agree with Rory as the story definitely sounds made up, or at least very much embellished from what might have taken place. Apart from the other aspects of the story, if his wife also uses the car, then what was is to stop her going shopping or elsewhere in the middle of the day? Anyone who knows anything about reptiles knows how extremely intolerant they are of over-heating. Just a few minutes in a locked car in an open car park in the heat of mid-summer and the animal would have expired. This is something someone experienced at transporting snakes in cars would be particularly aware of and would not overlook.
Someone forgot their thinking cap when they were inventing this story...
Blue