I've got no dog in this fight but I find it odd you'd not know how a car windshield is constructed.
Not so odd considering I've never had to change one in 30 or so years of driving. Other than knowing that they are laminates, I wasn't aware that automobiles used an identical plastic compound.
I just find it odd that people are using products that may not be approved by the FAA or the airplane manufacturer.... or health authorities. What happens when this automobile product is heated? Is it safe to use with fibreglass? Carbon composites? Does it break down into dangerous compounds in the presence of ozone, etc?
Why was aircraft rain repellent banned in the first place?