We have had the same issue. It is horribly scary and it makes me nervous to drive the car as it absolutely can not be good for the transmission to drop like that! We also took it to the dealer, who was unable to replicate the problem, so were unable to fix anything. I did write to Hyundai corporate (through their website) and think that is something that everyone should do. The more feedback they get on it, the more likely they will issue a recall for what is obviously a faulty sensor! Contact Us | MyHyundai is the link to submit a complaint/comment to Hyundai.