Now, I only have an auto Crossfire...
awww, you're stuck with a crossfire... poor wittle guy.
just kidding. welcome to the forum --
I also would guess that the manual function is electronically activated, we should be able to move the function to an aftermarket steering wheel.
good luck -- do a search for 'MOMO' or 'steering wheel' and read about what i went through when i 'attempted' to change the wheel.
as for performance, search around the forum for intake (just DIY; nothing available commercially), 'exhaust' (borla, magnaflow, etc.), 'upsolute' (chip), headers (for $1,400); you'll find pretty quickly there's not much around... short of spending $8-10K on a supercharger kit from the big boys (startech, renntech, klemman... at that point you might as well trade 'er in for an SRT|6).