Hydraulics

Ok, so picture this: You're driving down the street, and the silver Honda Civic in front of you is rocking back in forth, while moving. Like, majorly rocking back and forth.

Driving Brother 2, Brother 2's girlfriend, Cousin J, and some other kid to Walgreens.

Brother 2's gf: LUGGAGE!!!!!!!

and then, they start rocking back and forth, so hard that my car is shaking... it doesn't stop until Brother 2 hits his head on the window.