This is a tip I discovered while playing. It was a perfect ambush spot!

Location: NEW JERSEY

Directions:Where Observer Highway & Newark Street meet there is a save point (The Highway Hotel). Because there is that intersection there , traffic tends to get backed up and trucks keep respawning in that area. So if you have a shotgun (I sprung for the streetsweeper) you can just take out truck after truck and just rack up the cash. Your soldiers are close enough that they will join the fight. What's even better, is that if you pay off the cops they will be in that intersection patrolling and helping fight the guys in the trucks! I made alot of money off this trick which helped me buy out alot of businesses.