Anyway, ran a few laps this afternoon with TCS 0 and ABS 1 and, surprisingly, I seemed to have more control than before..not entirely sure what's going on there, maybe it's just a lucky day (I get those sometimes). Managed to improve my pre-ABS+TCS time by a tenth and am only 4 tenths off my combined PB Sector times:
I'm not surprised that you improved your time but I'm surprised you did it so quickly, this means you have some good wood to cut there.
Another thing in order to improve your times (maybe for the next TT), forget the auto transmission and learn to use the manual one, it will be a mess at the beginning, but when you get used to it, this will become a second nature, your fingers will press the proper button without thinking which one you need to press.
Manual transmission is not only beneficial to get the best of the engine, in some cars you need to shift before the red line and in others way after the red line, in this Audi R8 the best shift is near the red line so automatic transmission is not a big impact on times, but, if you use manual shifting you can unsettle the car at your will when downshifting at the exactly moment you want, this is beneficial (sometimes) to get more rotation at the entry of the curve, in some cars you can squeeze the torque at your disposal using a longer gear when in automatic shifting it engages a shorter one.
I recommend you a wheel, but if for whatever reason you can't buy one, I recommend you a Dual Shock 2 instead of the DS3, looks like there are more levels of pressure or at least it's easier to control the gas and brakes, I don't have one but I've read this info in GTP (I don't know exactly where), searching more about this should't hurt anyway.