i was thinking about the in-game leaderboards and thought how TiagoSantos could have possibly gotten a 12 second time, and i think i may have found something but it isn't working as of right now, this is what i think they did.

Drive a lap as normal when you reach the boosters and into the plane before the finish line turn around, aim left bost into the short wall and hit the respawn button and you respawn on the track just after the first booster were the current glitch is performed, i've attempted this many times and it has worked but the game doesn't count it as corssing the finishline and startign a new lap it just continues the lap you respawned on kinda like lighthouse loop.

this is all i have found thus far after a week of investigation and experimentation.