I bought an RER unit(Navigation) and installed it using the Coastal tech standalone mic and I have the LockPick also installed...just made it easier to hook up front and rear cameras plus I have the ability to put in rear video. Anyway the problem I am experiencing is when talking to someone if you are in the truck its fine but when you are on the other end it sounds terrible like there is interference or something. Anyone else upgrade to an RER and have stand alone mics..any issue? I am considering putting in the OEM mirror with the mic but I don't know what I need.