So dense, light bends around them...

Tom and Barney got out & locked the car in a hurry, forgetting to remove the key which was in the ignition.

Realizing their mistake, Tom asked, "Why don't we get a coat hanger to open it."

"No, that won't work" answered Barney. "People will think we're trying to break in."

Then Tom suggested, "What if we use a pocket knife to cut around the rubber, then stick a finger in and pull up the lock?"

"No," said Barney. "People will think we're too dumb to use a coat hanger."