Obviously we're pulling your leg, beckster. When you look at the Bonneville'* exhaust, there is a U-shaped bend that enters the muffler, so you're not completely crazy for thinking it'* the same U-bend as in a W body.
However, the U-bend that GP owners speak of is a different thing, which bends tighter and is more restrictive than any bend in our exhaust. For all intensive purposes, your exhuast flows plenty of velocity for you at this point. If you want to redo your exhuast you're more than welcome, but it might not do anything for you.
1997 SE w/SLE package
"White curse? I think it'* more like.... WHITE FURY!" - MyLittleBlackBird