I am sure people do. But the majority of people use via boards. Then the rest are mostly intel. THe rest are AMD. Most AMD people do use the mobile chip because it only draws 35W. THe Pentium M and Duo Core use the same, and are more suited for a car environment.
Also it is waaaaay overkill. How much power do you need to play music? The answer is next to nothing.
So why buy an expensive chip when you will never put it above 10% load?!