Continuity mistake: Leonardo is dangling from the railing of his yacht as the yacht travels at a high speed. In the next scene, looking out from a room with a large window, Leonardo can be seen still clinging to the railing but the yacht now appears to be motionless.
Continuity mistake: While Leo is trying to dump the sand into the bin or truck the sun changes between shots.
Answer: Just because someone is low income doesn't mean they can't own a decent car. Kate could spend what little money she has to pay for her car and still consider herself poor because she has no money left over after paying bills. Plenty of low income people still own decent cars because they are more reliable and require less maintenance than an older car, and are thus a good investment. Kate has three children, works two jobs, and goes to school. She has to have a good car to get back and forth and there's no way she could afford a major repair on an older car, so buying a new car is actually a smart choice for her situation.
BaconIsMyBFF