sometimes, i hear what sounds like a balloon losing air in the back seat, and an occasional pssshhhhhhh when first starting to drive and mph is under 45. I'll have them check it when i go for an oil change. I've got almost 4k miles on it already because of the many NY<>PA round trips since I bought it. I won't be doing those any longer so I'll take it to service in the next 2 weeks.