All the good stuff...
This is achieved by simply turning ESC Fully Off and then launching the car. Some people believe there is more to it than this, or it's some 'hidden' feature. It is not. It's literally the result of turning ESC fully off and then burying the throttle from a standing start. You can also combine it with the official Launch mode.
Not a difficult one to master this, there's a button - you push it and follow the on-screen instructions :) It very kindly talks you through what to do. If you leave ESC On (or dynamic) and the car in full auto mode when you do this, it will perform a Formula 1 level launch. Minimum wheel spin and maximum G force.
If you disable ESC and do this, you'll get a mixture of rolling burnout and then some traction as it shifts up through the gears. It does go, mostly, in a straight line thanks to the active rear braking, but do be prepared for a bit of drifting if the road surface is either on a gradient or does not provide equal traction across the rear wheels.
There are three modes for the various gearshift related noises you can select.
This gives you soft, smooth and silent shifting. Any speed, any gear, just seamless transitions and no pops or whipcracks.
This one gives you the pops and bangs of cutting the ignition during shifts. It only occurs above 3000 rpms (because that is when the exhaust flaps are open) so even if you have the USA/MSO ;) exhaust fitted, you will still only get them above 3K.
This uses a combination of ignition cut (between 3k and 5k ish) as well as the McLaren 'Inertia Push' shifting when at full throttle and upshifting. This is basically a Clutch-Swap, literally, instead of doing anything to the engine speed it just swaps one clutch for the other in the next gear. The 'inertia' they describe is literally the fact the engine was doing 8K and suddenly it's being instantaneously shoved against a gear that is doing 6K...
At lower speeds, Track mode will just do the pops and bangs when shifting at less aggressive throttle positions, for fun and giggles.