1) Car protectors 2) Front & rear impact absorbers 3) Slang for tennis shoes 4) Slang for breasts 
The fins on the front and back of a bobsleigh used by crew members when they're loading.
A supplemental device designed to protect a vehicles frame and/or body from collision damage.
Bumpers is slang for breasts.
You’ve got flippers and the ball—now how about those bumpers? Bumpers come in two varieties: passive and active. Passive bumpers just sit there while active ones bounce the ball back into play. Mushroom and dead bumpers are types of passive bumpers, while some active bumpers include the thumper, the jet, and the pop.