Ok, this is really strange. This may be a problem that is unknown until it gets worse or breaks. I have a 2001 Nissan Sentra 2.0. Got in it yesterday morning to go to church and had to turn around and go home halfway there because I had a burning rubber smell coming through the vents. I had the AC running at the time and “thought” I heard a slight wining sound coming from the front. I’m not sure if this is related to the AC or not. But anyway, I pulled over, shut the AC off, let it idle for a minute and drove it home. I left the AC off for safe measure and smelled nothing on the way back. This has only ever happened to me once in the 2 years I have owned the car. Any ideas? I’m afraid this problem is going to present itself again while going 75 mph down the highway and 2 hours from home.