The mid muffler you speak of is the resonator and replacing it with a straight pipe will likely have the same effects as doing it in the regular contour exhaust which can result is drone and rasp, plus I don't think it would give much gain.
Just my .02
Rick
------------------
Buckshot77@AOL.Com
2000 Contour SVT
Silver/ Midnight #1611
Born on 1/14/00
Borla, KKM, Upgraded Fogs w/ Parking Lights, heavily leaded right foot
Des Moines, IA
New Motor @ 20,959 miles
Born Again 2/21/01 (definitely not a Christian car though)