"Standard Assets" Car Audio Glitchy

I added the Sky Car to a scene that already had a FPS controller (the Standard Assets FPS Controller), and I could hear the car's audio just fine. (When the car drove past the FPS camera, everything sounded great.)

But I deleted the FPS Camera and created a "follow" camera on the car, and now the car's engine sound is gone, or glitchy at best.

I tried moving the camera closer and further, and tried deleting the camera's audio listener (and adding an audio listener to the car itself) but no luck.

All I hear are tire squeal sounds... and those are a bit glitchy as well. Engine sounds are basically gone.

Any idea where to start looking to fix this?