Mini cooper rear window crumbled

OK, so my neighbor and I are standing next to my car last Thursday afternoon and we hear this loud POP that came from my car. Then, my rear window crumbles. Nothing hit it, it wasn’t broken 5 minutes before. It was about 80 degrees outside, with a million percent humidity.

Here are my questions,

How the heck did that happen and how can I get Mini to pay for it since it’s still under warranty. They claim that they don’t have to because there is no proof that I didn’t break it myself.

Find a Mini board and see if others have had the same problem.

I would think that you should file a claim with your insurance company, as part of comprehensive coverage. Heat buildup inside the car most likely caused the damage via the pressure created. The damage is not a warranty issue.

Good idea, but there’s no ‘pressure created’, any air expansion just goes out the ventilation system. Otherwise cars here it Dallas would be popping windows left and right!

I did look on a Mini discussion board (motoring USA) and couldn’t find anything. I’m trying to find a way to get the Mini dealership to pay for it. I live in Austin where it hovered around 100 degrees every day last summer for three months and I never saw any windows popping. My insurance will only cover the window after the five hundred dollar deductible (and the estmate is $900). Also, my husband, an engineer who specializes in relief valves/pressure doesn’t think it could happen.
Thanks for the suggestions, Keep 'em coming!!

Glass is a funny thing. It’s very strong, but the slightest flaw, even one you can’t see, creates a weak spot, and the glass can shatter from a minor impact or just thermal expansion.

You’re not the first person to whom this has happened. Get a few estimates and turn it in to your insurance company.

Pressure does not build up inside cars, even when they are parked in the sun, because there are plenty of vents that are always open to the outside air, equalizing the pressure.

Unfortunately, you are the victim of a defective piece of glass. It happens from time to time, and nobody is going to want to pay for it. This type of problem normally originates as a tiny, maybe even invisible defect in the glass and can cause the window to break for no apparent reason. If the car is brand new, you have this as an argument, but the older the car is, the less this argument will hold up. After all, who would maliciously smash the rear window on their car just to try to get a warranty claim?

I guess the dealer’s thinking ‘that guy might have backed into something, a kid might have thrown a rock, who knows?’

You have a witness to the window breaking on its own.
Ask your witness if he will join you on a trip to the dealer.

When you are both there, you tell the dealer that your witness was there when the window shattered on its own, and that no external force was exerted on the window to cause the damage. Remind them that there is no proof that you did in fact cause the damage, and you in fact have a witness that was there when it shattered, and that you would rather not have to take them in court, where you will win the case.


It happens all the time on all cars. The worst thing you can do to a car is drive it. That type of glass can go at any time unless you are trying to break it; then it will make you look silly by not crumbling.