Has anyone done an "auxiliary in" from the CD changer connection? I have the Nakamichi premium stereo in a1999 ls400

Factory Radio Service added an aux-in to the Nakamiche head unit in the 2000 LS400 I sold in 2014. I got the version that had an on/off button on the face of the head unit and the aux in on a cord but they had a variety of configurations and may still offer a Bluetooth AD2P version. Turnaround was very quick and sound quality was excellent. The on/off button looked as if it could have been original. Others on this forum had aux-in added to their head units. Here's a link: https://factoryradioservices.com/