Like Harvard has just said, fuel economy is the worse thing about Mazda's as a whole.
The main thing to look out for is the laquer bubbling on the wheels and boot badge. They are quite noisy at motor speeds, especially in the back. The original battery's are shockingly bad, Iv seen them go flat in less than a week. There is a panel in the passenger side foot well, that has very weak clips and tends to get kicked off by accident.
There's no real mechanical issues to look out for.
I used to see an occasional one that had a faulty dash display.
Day to day running they are a fantastic car, overall bad points I would say they are underpowered and a bit heavy on fuel.
If you go to see it and need to know anything particular feel free to drop me a PM.
HTH