Transmission went out at 50k miles $2000 to replace.
O2 sensor failed at 55,60k miles $200.
Oil pressure sensor failed 65k miles $100.
Water pump failed 71k miles $600.
Car broken into bunch of times $1.5k worth stolen and $150 for broken window.
The car is pretty reliable, but the 2.0 is slow... its just slow 0-60 is 11 seconds... I put new intake on and it did not change much, but sounded a little better. handling is OK...
For some reason the mazda is a target for breakins at my experience. The window just has to be pulled and you can reach your hand in to pull window open. After someone did this the window never shut the same it would go in at an angle and not shut right so water leaks in.
The paint fades pretty fast and the headlights turn yellow quick.. I replaced them for new clear ones though.
Stock sound system sucks replaced it, but took a while to find all the buzzing noises.
Water leaks in trunk.. did not bother to fix.
Its hard to find parts/aftermarket parts for the mx6 to. Its not that popular of a car. people that have it like it, but there are not enough of them for the performence parts people to make parts for it.
Overall.. It's a pretty solid car, good gas econ maybe high 20's. Pretty reliable, AT trannies burn up from what I know though (ford makes them)..Easy car to work on good amount of space under hood. If I were to get another one I would find a good shape body and drop jdm 2.0 motor in it 170hp.. anyways.
I have an mx6 with a 2.0 and manual transmission. My mx6 was pretty quick when I got it. I put in some platinum spark plugs, now it goes even better. Just thought I would share this.