Much like the other drag race challenges this can to be done through the Parking Garage in the Outback/Redstone Airport. This can be also be done with online freeroam and create a blueprint at the Redstone Airport (thanks Nautius Maximus), but this solution focuses on drag racing through the Parking Garage.
As the challenge states simply grab or purchase any Lamborghini and fast travel to the Parking Garage and enter (I did not try this with the LM 002 but I have to imagine that that will qualify as well. Please post in the comments if you find otherwise). Wait in the lobby until '
Join Showdown Race' appears, and of course press
. Do not 'Start Online Session'.
Simply race 3 times to earn the challenge. You do not need to win and most Lamborghinis will be able to complete the race by the time the 30 second timer ends.
Video for reference where the Parking Garage is and what the '
Join Showdown Race' screen looks like. Challenge pops shortly after completion of the 3rd drag race: