IMO the big key with paints like that is to do more/better prep than you think is necessary. Milder products that are still abrasive, used after the 3M FI will bring up the shine a *lot*.
After I get our Audis (currently '00/'01 A8/S8 but previously '00 A6s) apparently perfect (and that's in really demanding lighting) I further burnish them with mild products. IMO you can get a much better finish than Finesse-It will provide, and *that* will make the difference. The last 3M polish I use is PI-III MG 05937 and I use milder stuff after *that* on my S8 to get the right gloss.
The 1Z Pro MP I like is getting hard to find, maybe consider the
Menzerna FPII or the BF/Menzerna polishes made for CeramiClear (the paint on your Audi is almost that hard anyhow).