This might have been very helpful when Matthew and I were in Puerto Rico last month. To make a long story short, the windshield of our rental car fogged up when we were 30 minutes from home, and no amount of scrubbing (inside and out) or running the defroster (which ran only cold air) worked. Even the three cops we hailed couldn’t help us, so we ended up having the car towed back. I’m currently in a battle with Budget to get that reimbursed. Now if only we’d had a pug with us!