Ok, I understand money laundering (for the most part) but I don't understand the point of it in this movie. More specifically, I don't get the scene where Brads Jr and Sr launder money by buying a car and then reselling it somewhere else. How does this hide the dirty money? Also, Brad Sr. resells the car for several hundred dollars less than what he bought it for (meaning he lost money in the process). Can someone explain this to me?
That's laundering money. By putting it into the system and getting it out again "washed". Losing a few hundred dollars in the process is certainly worth the payoff.
The process doesn't really have anything to do with the second dealer making a profit.
It has more to do with the fact that the stolen money is likely traceable by serial number. So if they walk into a car dealer paying cash, they can use bogus information and trade the traceable money for an asset (the car). Then the car is resold (albeit for a cheaper price) in exchange for money that isn't traceable (or isn't likely to be traced).
They might lose a few hundred dollars in the process, but the result is 100% untraceable profit.