That's not a good analogy. A broken water heater does not render a house uninhabitable, only provides for uncomfortable showers. Unless you're like me who will take cold showers, but I digress...
A shattered sunroof renders the vehicle pretty much useless unless you like driving around with small pieces of glass falling into your eyes, on your clothes, etc. It also makes the interior no longer weatherproof, and subject to the elements.
A better analogy would be if you bought a house and the roof flew off. Or one of the exterior walls fell down and then you had to rent a hotel room until everyone agreed upon a method of repair, and who's paying for all of it.