I had a horrifying experience with mine, a 2002 model. There were issues ever so often, but what took the cake was that, 6 years in, it started to burn oil, as,

I had a horrifying experience with mine, a 2002 model. There were issues ever so often, but what took the cake was that, 6 years in, it started to burn oil, as, from full to low on oil in 100 miles. The car's diagnostics saw nothing wrong, so even knowing what to fix would have involved opening the engine up, and that's a lot of labor. Then you might end up with a costly part replacement on top. The actual recommendation from the mechanic, given that the car was still relatively new, was to fill the oil up and trading it in to a dealer without disclosing the problem, that there's no way they'd find anything wrong with it in any pre-purchase inspection! So... yeah, Mazda6, not so much.