Yup! Backing with a rear rack should be done most cautiously. Consider the car top rack. Of course then, if you forget it's there and the bikes are attached, you might try to enter your favorite parking garage and....! Over the years I have had both kinds and the rear rack is best despite goring the odd tree or you, walking into it at night! The reason no one was cut is you have (or had) safety glass, so called because it shatters into tiny fragments when impacted. Use a shop vac. The glass is easier to deal with than the 'urpage' my daughter decorated the inside of our Opel wagon with. Seems that miles of coastal highway mixed with chocolate chip cookies, didn't.:>)

CB