Re: need help on identifying devices near Subwoofer
The basic part number - 18C808 - is what should describe the part. It is definitely part of the audio system. Ford speakers carry the basic part number 18808, the inclusion of the 'C' I don't know. It looks like an amplifier with those cooling fins, but amplifiers usually carry the basic part number of 18T805 or 18T806. The prefix 2C6F tells which model year and model line the part was first introduced for, and the suffix AA tells the variable number or revision number of the item.
As 351cid said, you could take the number to your local Ford dealership parts guy for clarification, although service part numbers don't always exactly match assembly line numbers (prefixes and/or suffixes may be different).
Easiest way would be to ask someone at your local Ford service department - they are sure to have changed one of these at some time, and would know exactly what it is.
BA GT #0909 - Manual, Citric Acid, Stripes, Sunroof, Premium sound, FPV Steering wheel and Mats.