My 2015 MKS recently had its first flat tire -- really flat. When my husband went to put on the compact spare, he discovered the lug nuts from the 20" factory wheels would not tighten down. In effect, my spare could not be used as is. He eventually found the correct size lug nuts on one of our trailers and was able to install the spare so I could drive to the dealer for assistance. The dealership could not explain how they sold me a car which could not have a tire changed without a different size lug nut being used. Has anyone else run into this? Shouldn't the car come equipped with everything necessary to change a tire?