It sounds like it's coming from the air pump, is there a way to quiet the thing up?

Is the belt loose and slipping or very worn?

It's not slipping or loose, there's just a squeak when the car runs.

Try a new belt...inexpensive

Belts squeak when they are worn out, glazed, misrouted or wrong for the application. Belt dressing is not a fix, its a diagnostic tool. Applying belt dressing will confirm a faulty belt rather than a faulty bearing. Over the years, I've used a bar of hand soap applied to the bottom side of the belt to verify a belt caused noise.

Belts squeak when they are worn out, glazed, misrouted or wrong for the application. Belt dressing is not a fix, its a diagnostic tool. Applying belt dressing will confirm a faulty belt rather than a faulty bearing. Over the years, I've used a bar of hand soap applied to the bottom side of the belt to verify a belt caused noise.

2nd that. I spray some PB blaster on the belt (b/c it's not really that flamable, you can shoot it into a propane torch and it won't ignite). If it stops for any period of time, it's the belt. Tighten if wobbly, replace if worn.

Ahh cool. I'll have to pick up a new belt then. Thanks.