Hi,
Took mine up to Mrc in may and had to leave her for a few weeks with a gearbox issue which needed sorting.
I can remember quite clearly at the time Doug sat me down & said to me the biggest performance/per pound increase is going to be doing the decoke !! (depending on severity of inlets).
After that a stage ( your choice) map then the other bits precats on a standard pipe, Manifold,cold air feed & trumpet diffirent air filter ..... , one thing he did question was the fuel I used , I unashamedly replied Esso high octane , he shot me down & said that was the worst premium I could use due to the 97 ron at best rating & suggested Shell or to my surprise Tesco Momentum 99 ron I switched upon arrival home.
I delayed any tuning as a new box was worst case gonna see me in for best part of 5K + fit , Painful waiting for gearbox inspection however got some not so bad news .
I had the full Monty stage 2 all in which transformed my ride into a docile mild mannered A4( with the linear throttle) until the *S* Button is pressed & unleashes the full fat tarmac beater

, point at the horizon & watch the revs/mph & scenery distort in the radial blur

(believe me I heard this before and was sceptical to say the least) .
My advice save it up and do as much as you can at the same time the drive home will smack you in the face but leave you grinning from ear to ear every time you think about it from that day forth

Happy motoring whatever you decide.