Not so sure all the speakers would.
Audi front tweeters in the Bose system are located in the A pillar, not in the door skin, and are complemented by a centre channel located in the middle of the dashboard to rais the lower midrange out of the footwells.
The door woofers should be a pretty much straight swap.
There are then two rear woofers in the rear doors (which again should fit), and a sub mounted in the boot over the nearside left wheel arch (when I say sub, I mean almost a sub - more bass than components, but if your used to a REAL sub bass you could never call the Bose unit a TRUE subwoofer).
Don't know where the amplifier unit sits, never found it to date.
Be warned, some that are removed sometimes suffer a bit in the de-installation process and can be problematic. Its a decent sound against basic OE kit (for the lazy arse like me), but its no match for a well set up Alpine set up.