All kinds of problems that you can think of.
Major things:
Engine over heated multiple times
Starter
Idle Air Control Motor
Radiator
Starter
Alternator.
Minor things:
Power Belts
Power Windows.
Have spent a lot of money on this piece of junk.
Will never buy a Mazda again.
It is a piece of junk. Don't buy.
Compared to other reviews on here these vehicles seem to be very reliable, you just bought a lemon that's all.