Looks like Aero and Tyres tuning are useless almost all times (at least for me, you need to spend ~15 seconds on it), but i still need to research it more. Gearboxes are weird thing, for most cars i used low, but for some i really needed high. Gamepad is really effective on slow cars for getting faster times, but for fast ones you get only more stability in controls.

Wrapper: nGlide Controller: DualShock 3 (Stick steering)

Twitch (with music and mutes because of music):