Video Description:

The Crew - Synchronized Spinning - Earn 3,000 Bucks from a Multiplayer Stunt Combo. [Bronze / 15G]

This can be done in the same way as the "Show Off" trophy and achievement. Head to the Bonneville Salt Flats north of Las Vegas. Drive from one end of the salt flats to the other with full speed while drifting left and right (as if you were driving a slalom). A crew member needs to stay with you all the time. The more people are with you, the higher your multiplier will be. All crew members have to stay within a radius of 100 meters (110 yards). Have the other crew member(s) drive slowly behind you while you drift. They should drive normally without drifting. If they try to drift too it will get too hectic and you might crash into one another. If there are no crew members within the 100 meter (110 yard) radius it won't count as a "multiplayer stunt combo" anymore.
I used the full stock "2010 Dodge Viper SRT-10 Coupe" for this (without any tuning), but it also works with any other fast car. You can get the Viper on Uplay for 100 Uplay points.
You should also be level 50 and max out Alita's Daredevil ability before doing this. This will massively increase the bucks you get. On low levels this will be much tougher and you have to keep drifting much longer. If you have trouble with this, then have a full crew follow you to get a "x3 multiplier".