Korean cars are the top quality vehicles by a growing stretch. Japanese brands on the other hand are slipping down the rankings table, falling below the industry average for the first time in 29 years. That's according to the latest J.D. Power Initial Quality Index report which has just been released. The study measures problems experienced by vehicle owners during the first 90 days of ownership. In terms of nameplates, Porsche (POAHF) ranked top for the third consecutive year, followed by Kia (KRX) and Jaguar (TTM). Infiniti (NIS) was one of the most improved brands in the study, coming in at number 5. Though vehicles are becoming more high tech than ever, technological advancements continued to cause problems for the industry. 'Smartphones have set high consumer expectations of how well technology should work, and automakers are struggling to match that success in their new vehicles,' said J.D. Power's vice president of U.S. automotive quality Renee Stephens. 'However, we are seeing some OEMs make important improvements along the way. What’s clear is that they can’t afford to wait for the next generation of models to launch before making important updates to these systems.' Stephens added. Overall, initial vehicle quality has increased by around 3 percent since last year.