Yes, an obvious and valid flaw, I don't know why you are being down voted. A car with a roof-rack word would prevent the bus passing, assuming the driver sees it. Not to mention cyclists.
It's almost that time of year in Boston when many people move c. Sep 1. Some get "Storrowed":
http://realestate.boston.com/news/2015/08/28/your-guide-to-a...