rds with a 2001 deck

It says RDS on my stock cd player in my 2001 coupe. What is RDS (radio data system)? How will that affect the installation of a new deck? Does the installation of a new deck involve new parts/harnesses?

RDS is a software program installed into the radio nothing more nothing less. There are no different wiring harness or anything that you can tell from the outside of the radio, it is all internal.

i was just confused because i was talking to the guys at best buy car audio install department and they were saying "if it says rds on the cd player than we can't install it because it needs a harnass that we don't have" which didn't make any sense at all to me.