While at my local window tinter today I began a conversation with a fellow customer who was waiting to have the windows of his brand new 2006 Eclipse tinted. He turned out to be a Sheriff Deputy of a nearby county (and a C5 fan!). I shared with him my line of work and we struck up a conversation. He told me about a box that could be attached to C5s that can change the auto transmission on the fly from smooth shifting to sport shifting. Has anyone here ever heard of such a contraption? He said it could be controlled from the driver at any time. Is such a thing true? Please C5 experts....what say ye?

I think this is what you might have in mind, although I think it is more than just a "box" - but like they say a reasonably competent guy can install it in an afternoon.

http://www.lmperformance.com/664/4.html

Thanks Lee, once again you come through!
You were right! I went to the website and found the"box" that is not a box at all. However, my question is, Why does the product say "Transgo Shift Kits 1994-1998?" Do those numbers represent the years of manufacture or are they just numbers and the kit is really meant for C5s from '98 to '04?

I'd call and ask. It says they are for C5s, but then says 94 98 -- doesn't make sense.

Well, 97 and 98 were the early C5s, so in may be this particular model fits late C4s and early C5s, something like that, and they have another kit for later C5s.