i feel id be paranoid about going with a tune if i was still under warranty but since im not i didnt hesitate. if the protune is from a shop and a conservative tune and not trying to push your car to the limit then you shouldnt have any problems. im cobb stage 2 AP tune and its alright, id like a protune so the car could get more power and a better tune but it runs fine and isnt having boost isssues or really bad knocks. im not sure how theres many consequences if your buying the correct parts and getting it safely tuned...youll just be spending alot of money but your doing it to make your car how you want it. Resell value can drop, harder to find someone interested in your highly modded car- safely tuned? beat on?