I have a 2012 model WagonR CNG which has been running absolutely fine without any mechanical trouble. I bought the car keeping in mind space and running costs. The design of the cabin makes it a very airy space which is liked by all. Moreover with the factory fitted kit, running cost is low which allows me to undertake trips to Gurgaon without breaking the bank. Overall very satisfied. Have done 56, 500 in the last four years and not really looking to change it very soon.
If you want a no nonsense city runabout that is light on the pocket and practical on the inside, I will recommend the WagonR to you