This fact contributed by the customer service representative who helped me purchase a new car radio at Best Buy today:
Aryeh: How much is installation going to cost?
Customer Service Rep.: About $55
A: I thought you guys do free installations on radios as long as I buy the wiring harness
CSR: We used to until we did this customer survey that said that customers would actually prefer to pay for their radio installations.
A: No way.
CSR: No, it's true