I got my new zen estillo lxi CNG dusky brown color on 3rd Nov 2010. I have driven it around 7000km and have not found any major concerned or you can say have not found any technical problem till know. have driven it on NH 2, NH 8 at a maximum speed of 130km/h. It has given me a mileage of 19kmpl on highway.
In city I prefer CNG due to increasing cost of petrol. With cng its costing me less the 1.5rs per km. the only problem I face is lack of leg space in the rare seats. rare shockers are also not that great. Overall I all give 4.8 marks out of 5 for this car. this is the best small car that any one can buy.