Okay, bad puns aside, I found a nasty little impact crack in my windshield this morning, looks like one of the neighborhood's little monsters threw a stone at it. It's about the size of a nickel. Do I really need to get this repaired? What exactly does that entail, how can you "fix" broken glass without replacing the windshield? Is it dangerous to leave it as it is? It is not broken through to the interior of the car. How much would a repair cost?