NYC: Mercedes Crashes Into SUV & Robs Driver At Gun Point

Crazy footage of a Mercedes crashing into an SUV to steal bag of cash at gun point from the driver.
The Mercedes must have been stolen by the criminals driving it. I mean who crashes a $120,000 Mercedes into a Rav 4 to take out a bag of $20,000 cash that wont even cover the cost of damages.
A number of questions come up such as:
Who was driving the Rav 4?
How did the guys driving the Mercedes know that the Rav 4 had $20,000 in it?
Why did the Rav 4 have $20,000 in it?