Bought a leftover in March of 2005. I've put on 55,000 miles since then. Had to replace both rear wheel bearings. The little Scion requires a whole hub assy. with integral reluctor be purchased, as the unit cannot be disassembled. $350.00 each. Add in some labor and it gets expensive fast. A cracked heater core also came at 44,000 miles. Wheel bearing failures and heater core breakage are not common failure modes on modern cars. The fact that the parts are not simple, reasonably priced or factory covered items makes me say, "Stay away from this car." I don't plan to get another one of these. If Scion recalls these and fixes them I might change my mind. Right now, no way.
Gas mileage. Purchase price. Nice child seat latch system. VVT helps low end acceleration and top end is not too bad for such a tiny little engine.
Upgrade future versions with reliable bearings. Something user serviceable would be good. Provide that to previous owners and I'll buy again. Don't and I won't. Also 15 inch tires puts replacement rubber in a catagory more costly than that of other commuter cars (like Civic).