 Experienced what felt like a transmission slipping problem before warranty was up - dealer test drove car with me and felt problem but wouldn't svc it without check engine light being on.  Light came on finally and fun began.  Murray, dealer,  monkeyed with car 6 times and light kept coming back on - problem grew worse till car would stop.  Had to go to Eastern Regional Office to open a case.  After 6 more trips to dealer and a special kia tech having to come out to look at car (tech had to come out for other cars that Murray couldn't fix too) and replacement of wire harness ($900 part which did not correct problem), another tech FINALLY found o2 sensor problem, light off for 5 days.