Here's a couple vids of my newly installed MSDS headers, along with the SHO Shop Ypipe,hi-flow cat and trubendz duals. It should give you a good idea on how loud it is.

Start-up
Cruising Speeds
Wide Open Throttle

'99 Cougar V6 ATX MSDS Headers.SHO Shop Ypipe.Trubendz Dual Flowmasters.AEM Intake w/GMK Extension.SVT Upper Intake Manifold.SVT Throttle Body.Custom Burned SuperChip.Ford Racing 9mm Wires.Ford Racing Tranny Cooler. 15.83@87mph