just wanted to point out few common issues which have happened with me as well as other owners of 2009 hyundai i20 magna petrol (may or may not apply to other years/models) -
1) terrible mileage: don't know how to elaborate this - the mileage maxed out at 6-8 kmpl over it's last 3 years' existence. A.S.C. guys are clueless, so are we, the owners and drivers.
2) keys stop working: the keys simply stopped working in the ignition after one year, another six months for the door locks. used the spare key from thereon, and 3 years later, you end up with 2 useless keys. A.S.C. suggest "misuse" or "lock damage", and try to get you to spend 6000 bucks or so on a full lock and key set change since "aapka to extended warranty nahin hai na". i say - call up the local hyundai office, and do not get off the phone until the service manager at the other end of the line ACCEPTS that this is a recurring problem in many cars, and therefore is a manufacturing defect. That's how i got my locks changed for free, btw
3) Horns: an annoyance more than anything else, the horns randomly stop working every once in a while, and eventually conk out. the mechanics simply have to open up the entire front grille to get to it, and tighten some loose wires or whatever, but this happens so frequently that i just paid 700 or so to the ASC to just change the damn honking machine.
this post served two purposes for me - venting out my frustration, and educating the good folks on this forum. others may comment as they see fit.