Car stereo volume goes up without turning it up?

Sounds like you may have a faulty unit. If you have any kind of warranty or receipt I would take it back and exchange it for a new unit if there is still time to do so. Or if you examine the faceplate it's poddible that the volume button may be stuck in. If it's a rotary knob then i'm assuming you have a bad unit. Good luck with it.

Check the ASL (Automatic Sound Levelizer) setting on the stereo. Usually can be set to ,'Off', 'Low', 'Medium' or 'High'. This is the option that adjusts the lever according to road and engine noise. When set to your liking, it's a pretty cool feature. Like in the spring, with the windows down........turns it up when cruising so you can hear it over the wind....back down at a stop light when there's no wind or road noise.