Can make around $120 every 3-4 minutes or so if you have a second controller available, otherwise still a respectable $60 every few mins.
Wobbly Burger.
This method has the added benefit of it being hard to mess it up too much, even if you wreck a burger or two you'll still get good money. There's no risk of crashing/blowing up a vehicle like the ambulance missions, no risk of tipping the ice cream cone like the ice cream missions, not getting money prizes in the quiz etc.
Fill up the Burger shop with money then take it all to the nearby ATM.
![](https://i.ytimg.com/vi/XZ6EZoCZJIc/maxresdefault.jpg)