I also test drove the Mazda 3 and wast tempted to get this car. Although it is technologically a better car (slightly), there are other features that are not so ideal, the smaller seating capacity (rear) seats and rear boot capacity as compared to the Civic.

The 18" rims though looks cool, but have you checked the tire prices for 18" wheels and at low profile too?

A check with friends who have had Mazdas, main complaint is the poor resale value, high cost of parts and poor after sales service at their SCs, not to mention there is only a limited no around.

Fuel economy for a 2.0 versus a 1.8 or 1.5T is a lot

Hope the above comments help.