I have a 1 year old Hyundai Elantra. Leased, still under warranty. The car started smoking out of the tail pipe, excessively. I took it to Centennial Hyundai and they claimed it was from a faulty oil change, resulting in oil getting into the intake manifold. Since I did the oil change elsewhere, it voided the warranty. They charged me $600 to fix the problem. Here's my issue: the oil change was 2000 miles ago. I believe if the oil change had caused the problem, it would have been evident months ago. So, I won't be going back to this dealer and will be switching away from Hyundai.