Did the OP ever say he needed it that fast? He said he was more than happy shifting his A4 manually.
Someone gives a reasonable option, everyone instantly wants to compare it to something completely unreasonable.

 

Seems to me he wants rid of his POS GM automatic.

If you are asking for a sequential box, you want fast shifts.

 

I'm looking into the sequential shift as a means of avoiding the joy of trying to install pedals up under the dash to go with the M6. May still go that route one day.

I want a manual shift for 3 reasons.
1. I like to control first gear long enough to get across the intersection before hammering it on the straight.
2. I would like to dump the clutch and leave a little rubber just to "mark" my territory like any other male beast of the wild.
3 It feels more like a "sports" car. Just for the FUN of it.

I do not want to spend $5k for FUN. It still is, what it is.

 

My first experience with an automatic sportscar was a high school buddy’s 1988 mustang gt 5.0 (in 1993).

it would take forever to do the 1-2 shift, and then shift hard into 2nd. There was probably something wrong with it.

the manual sportscars (of the era) would rocket on by as this thing would shift

 

Who knows? Who can measure that, among us?

GM's been making multi clutch transmissions since the 50's...and yes, with the proper orifices and line pressure, they can shift lightning fast. UNFORTUNATELY, GM severely botched the roll out of "paddle shifters" in the C6 by:
*implementing susper slow electronic controls (to match the super slow e-throttle!)
*Not locking the converter immediately in each gear after any/all shifts
*Too low line pressure and small orifices
*ALL BECAUSE they wanted it to behave like a Cadillac.

So, we got lame-o, slow, delayed shifting, sloppy/slushy turd auto trans with "paddles" on the steering wheel. Yippee. They COULD have been on par with any other DCT's or SMG's that were out at the time, with better control...but they didn't.

I don't see why you couldn't take a 6L60e and put in the right hardware, then control it w/the right software to provide instant "slam" gear shifting (like an older hydraulic control trans w/a shift kit and manual valve body), followed by instant converter lock after any shift, and above, say, 5 mph in first gear? Something like that w/some tuning would create about the same effect as a DCT. Only detriment would be weight and slight inefficiency.



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For a sequential you'd still need to figure a way of controlling the clutch for starts etc. To avoid that you'd need a robotized transmission (single or dual clutch) such as the Porsche PDK or BMW SMC