Proof of Concept.
This run wasn't clean at all and yet he still got .3 away from WR
Luigi's Raceway 1:43.861(new strat?) - YouTube
You start a drift turn to one side and then just as soon as you get the blue MT sparks you boost, jump out of it and turn the other way. It can be used to gain a tiny bit of time on straight aways if done correctly.