An enclosure system for open-top vehicles is described. The enclosure system may include a top system coupleable with an open-top vehicle, the top system forming a top surface among a rear gate of the open-top vehicle, a first side of the open-top vehicle, a second side of the open-top vehicle, and a wall system, the top system, the wall system, the first side, the second side, and the rear gate of the open top-vehicle forming an enclosure. In some implementations, the top system may include top frame members, rigid surfaces, and a removable top panel. The wall system may be coupled with the top system and include a rigid wall extending between the top system and a floor of the open-top vehicle, the wall system separating the enclosure from a passenger area of the open-top vehicle.