Ann I sometimes travel to Houston/Galveston from Oklahoma City.....I have the same problem and I have chosen a risky but necessary tactic.....I eat in drive throughs only and park close to eat the food.....then I run in to the potty with the doors locked and the AC running....I try to make this less than 5 minutes....sometimes if there is a RV nearby.....I ask the family to keep an eye on my locked car..
I have even left a sign on the dash saying that I have an alarm system that disables the car if it is entered improperly. Actually that is only partly true...but if there is not a trustworthy looking family nearby....I resort to this
It is a scary problem......I would be devastated if they were stolen....but I can't hold it for 9 1/2 hours.
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Max and Maggie's Mom