I own a linea top model fully loaded version. Lot of problems:
air conditioner does not work effectively, you feel like sitting in front of a cooler not an AC
the mileage is 5-8kmpl. I have decent driving skills. I drive an maruti esteem as well as get 14kmpl out of that.
finishing of the car is not good - you will find many loose ends, especially in the bonnet
service centre is pathetic. just visit them once and see for yourself - no one to attend to the customer. no delivery on time (it takes 2 days for them to service, you give the car today and get it tomorrow!!)
Best part is, my car is only 20days old and these are the set of problems I face... imaging the older ones :) Btw, you can test drive one vehicle which is old and you will notice the gear box is not smooth at all.