OK, I am not too excited about paying $100 for an AUX jack and another $70 for the condenser to quiet that pesky engine noise when using AUX input on chargers.

I found TSB T-SB-0067-08 while researching the issue which identifies the following 2 parts that should be replaced. If someone has a good resource for used scion parts or has these parts they can let go of please reply or PM me.

86190-12020 - ADAPTER ASSEMBLY, STEREO
Toyota - ADAPTER ASSEMBLY, STEREO Part Number: 86190-12020

and

86516-33020 - CONDENSER
Toyota - CONDENSER Part Number: 86516-33020

(edit) I actually don't really "need" the condenser since I am installing a bluetooth receiver and mic, but I figured I may as well make it right. It has also become evident based on the TSB that I will need a wire harness (WIRE, CONDENSER - 86237-33010 http://www.toyotapart.com/86237-33010.html) to interconnect between the AUX port and condenser. The other end of the Condenser plugs into the factory harness (previously plugged into the AUX port.