Wedding tradition - cans and boots on the bumper?

Aside from being immensely noisy, and symbolic in the old-era movie trade - what were the origins of tying tin cans/boots to the bumper of a wedding ‘getaway’ car?

A search in Uncle Cecil’s (and the SDMB’s) for ‘Wedding/Bumper’ failed. I’m hoping someone (Unca Cece?) can shed some light (or at least some shoestring) on the subject.