A vehicle of station wagon type typically used to perform intercourse within. To be classified as a slammin wagon, the vehicle must have the ability for the back seats to be lowered, have enough space for a variety of sexual positions, have dodgy suspension so the sexual motions are greatly exaggerated to outside observers, whilst still have the ability to perform drifties. Slammin' wagons have been known to be very romantic and comfortable places for sex, with the earliest 'Slammin' Wagoners' dating back to 1982 in their Subey's, the most versatile vehicle ever built.
Stupid, whiney, obscenely hot women: "I've had it with this party, I'm tired. Do you have a bed for me?"
Player who know's how it's done: "Nope, but I do own a slammin' wagon."
Girl: "OMG, I want you inside me."