I think it is pretty good.
The driveway at work passes the front of the building, and my team are located about 15 meters back from the windows on the 1st floor.
One day last week after I had parked my car and got into my office my staff asked why I liked Vam Halen.......
I have the rag top (so the sound probably travels more) but was still surprised they could hear the stereo well enough to ID the band!!