Hey Hey Hey! How good to compare 1.0 ltr engine car to .8 ltr car? Kwid and Tiago are both different segments car, how one could imagine to differentiate between two of them. As per current market scenario Kwid is ruling over TIAGO, we all know aftersale service of TATA.
You haven't mentioned anything about the transmission and its quality, the shifting of the gears (how smooth etc). It's an unpardonable lapse. Does either car offer automatic transmission??