i think ur still confused...u need some detailed comparison. i have city 09 new shape.if its a one man car, go for city. if ur married go for corolla ...u thinking why?
i have kept both as personal cars. ill let u know.
look, thing is if u live in isb, single, go to office, in evening u hang out etc a city will suit u best. i kept a corolla n got rid of it in a week as it was so boring in already a boring life. in the above given scenario city will bring a smile on ur face. Its fast, nimble, maneuverable at high speeds, clutch is soft as anything, breaks are great, steering grip and its material is very grippy, ac works like a window ac in ur home, variety of colours, a cave in a shape of a trunk coz u sit on a petrol tank. but the moment u are on an unpaved road that is the moment when you cry, all your grip,ac,breaks etc are multiplied by zero and you look at a passing floating corolla with a pupy face. dont forget city has no safety beam in front, rear and sides. that is why it gives you a 0-100 feeling kind a thingy on signals.
Corolla xli(as u only wana compare xli) will give you a feeling of a bigger car with ghumanay walay sheeshay, ony 2 colors are common. its ac is not up to the mark. had an altis new shape(1.8 not 1.6) its ac is just like a 1000cc alto. may be i got the wrong car but still after having heat repellent windows of saint gobain it was hot inside.same will go for xli, its pick is slugish. but lil bit safer thn city. in the end of the day its up to your requirements what you want. in resale both are good now. my city gives 14sh in city with 50% heavy foot. corolla will give 9-10 in local. as far as ur cng is concerened if it works in prius and rx8 it works in every car. your question will be will it harm anything? if you have made up your mind to go for cng thn dont think about the harming factor.
City is a bad boy car and corolla is a mature ,comfortable, lil bit safer thn its rival.
hope it will help you to decide