Leather covers will protect your cell phone from a variety of damaging circumstances. They will do absolutely nothing if you happen to leave the phone on top of your car.

It will do even less to protect your phone if you leave it on someone else’s car.

FAIL



edit: Someone else, left their phone on my roof. At approximately 50mph, my car’s gravitational field altered so as to repel said cell phone off the roof and into the highway traffic behind me.