Actually, most of the problems we had were fundamental design flaws e.g. a Toyota my wife had where the instruments (speedometer etc.) started cutting out occasionally - problem was tracked back to, of all things, the sunroof! There was a small leak and the electrical connectors for the instruments were in the bottom of the passenger foot-well - where the water was collecting from the sunroof and shorting things out.
Similarly I had a VW that was prone to flooding the interior due to poor design of the battery compartment - if the drain hole from the battery compartment was blocked it would overflow into the interior of the car (we're in Scotland so problems inevitably involved water).
Edit: To anyone asking why we bought a car in Scotland with a sunroof, I do wonder and we'd never do it again!
I don't especially want a sunroof, as they inevitably leak, but it's becoming increasingly difficult to get a car at anything other other than the base trim level without sunroof - and when combined with other requirements I have (e.g. sat radio) presence of a sunroof is one of the first things I'll compromise on.
Similarly I had a VW that was prone to flooding the interior due to poor design of the battery compartment - if the drain hole from the battery compartment was blocked it would overflow into the interior of the car (we're in Scotland so problems inevitably involved water).
Edit: To anyone asking why we bought a car in Scotland with a sunroof, I do wonder and we'd never do it again!