This was performed by our friends from DCC Xpress installations.
They offer high quality WOWSound installations for a flat rate complete with free return shipping!
You can find them at:

These items are available in the WDK-KAT-2 which was used for this installation.
AK-MB1 Motherboard with Keep Alive™ WOW121-Diesel Decoder 28mm Round WOWSpeaker
Click here for more information on the WDK-KAT-2 and the rest of the WOWDiesel Kits line.