I just had my Q50S (3.7) dynotuned on Thursday - gained 20 HP in over 90 degree shop temps with Uprev. Had to take a break to let it cool down at one point.
Martin (Z Fever) did manual pulls up to 4th and then wound it out to 8000 rpm. He raised the rev limiter to 8000, removed the brake / rpm limiter (whatever it's called, but now I can brake and get the revs high and the tires ready to go!), adjusted A/F across the board (got rid of check engine light from mods). Aside from A/F mixture, I have three new tune sets - manual sport with incredible shift feel, auto sport for mode select (not quite as aggressive as manual shifts) and valet mode with 3000 rpm redline.
Took it to the dealer and had four new tires put on Michelin Pilot Sport A/S 3+. 275/35-19 and 245/40-19 The new rears were wide enough that I had to take off my 15mm spacers but left the fronts on. The Michelin's are quieter than stock and have a really nice rim protector.