you are considering the maintanance and consumption ,, you should consider 1.3 XLi rather than 1.5 EXi with CNG,,
i would further prefer new XLi ,,, because for me ,, civic models below 2006 are not that spacious ,,,, Xli is far more spacious than the older civic models ,, apart from the technology and drive Xli is a better option for the family as far as comfort is concerned ,, i have a 2.0d saloon and i have been into the civic 2005 exi ,, i sat on the back seat and my legs wouldnt fit in ,, the front seats are fine ,, the back seats of Xli are designed in such a way that they give a cozy effect as they are deep ,,,,
If you are comparing the drive , technology , drive train , shocks , , brakes ,, go for Civic