Hey saw your vids on youtube and have been a member of these forums for a while.
Were you Flowmaster mufflers welded on or did they just use a torch and cut off your OEM ones and clamp the Flowmasters on?
If they clamped them are you in a area where salt could play a role in deteioratiing the exhaust system?
I know for me it could be a serious problem if what I read is true. -That using clamps instead of welding the mufflers to the exhaust in a area that uses salt alot during the winter months. (I am in the Chicago Area)