Let me admit at the outset that I dont own a Spark or for that matter any Chevy car. But my closest friend owns one and I know about the car almost as good as any owner.The car itself is good. It is nice to drive, the build quality nice, the location of the speed and odo cluster at the centre of the dashboard makes it easy for those sitting on the rear seats to note that. Good for those who ride chauffeur driven cars, though the Spark is generally an owner-driven car.
However:-
The fuel efficiency of the car is not as much as what is claimed. My friend is getting around 13-14 kmpl, in mixed driving conditions which is of course not bad.
Service centres are few and far between.
In spite of the tall claims of 3 year free maintenance, it is really not so. The service centre makes you pay on some pretext or the other.
Once the 3 year, 45k km warranty is over, one needs to be prepared to pay through the nose as both servicing charges and spares are costlier than that of Hyundais or Marutis.
I am yet to figure it out as to why Spark doesnt sell well, in spite of mouth watering initial price and being a quite good car. Overall, my friend doesnt have many complaints, but I wouldnt recommend it only because of servicing concerns.