I bought a pair of 4 inch heel leather knee high boots from ebay. I tried them on in the car they fit perfectly.
I wore them home from work driving. I had to make 3 stops. First was at a gas station. I left them on and pumped gas. Second was at a deli for bread, I left them on, third was a supermarket. I shopped every aisle in a supermarket in 4 inch leather boots and no one noticed. I came in my pants