Motorweek just did a review on the spark.
2013 Chevrolet Spark | MotorWeek
Didn't have too bad of a review. they also got 39MPG out of it - which is pretty good. Usually when they do these reviews they drive them somewhat hard and get somewhere between the rated highway and city mileage. I bet it could easily hit 45mpg if you keep it easy on the highway.
They seemed to like it, for what it was.
I'm going to try to get a test drive of one today.