Strange whistle

I took my car in a month ago for a routine oil change and have noticed an intermittent "whistle " inside the car since then. It can be heard when stopped, accelerating or braking and my occur only once or twice in a 15 minute drive. It is as if there is a stowaway in the car. Any ideas?

Sounds like a vacuum leak. They may have disturbed a vacuum line during the oil change. Pop the hood and try to zero in on it.

Open the hood and see if you can hear where it’s coming from. Could be a belt or vacuum leak.