I spent some time digging up old threads that have some actual useful information for you. Sadly, most of them were dead ends. Hopefully helpful nonetheless.
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Type: Posts; User: bethridg
I spent some time digging up old threads that have some actual useful information for you. Sadly, most of them were dead ends. Hopefully helpful nonetheless.
...
C7 S6
Can be had on the used market for ~$30k all day
420 hp, APR Stage 2 tuned to 600-ish hp $1.5k
C7 RS7
reaching mid-$50k's
560hp out of the box, APR tuned to 760hp $3k
Your efforts would be better directed towards a C7 S6 or better yet an RS7 if you're into the sportback look. What you will spend in time/R&D/buckets of cash chasing this rabbit is readily available...