Answer
The tomato will land on the gound.
Work Step by Step
The velocity of the truck, your velocity and velocities of each tomato (before they fall of) is equal, so there is no relative motion. When the tomato falls off, there is still no relative motion in the horizontal direction - what will change is that the tomato will start gravitationally accelerating vertically downwards so it will appear to be in free fall. For it to hit the car horizontal relative motion is necessary, but because there is no such motion it will hit the ground before you pass it.
