A cargo carrier system including a tray-shaped base and an inverted tray-shaped removable cover. Means are provided for mounting the base to the roof of a vehicle and for attaching the cover to the base. The cover and the base have continuous flanges extending outwardly in a horizontal direction with continuous resilient sealing means between the flanges for preventing the entry of dust or water into the space between the cover and the base. Resilient sealing means are also provided around the peripheral bottom of the base for a secure and protective mounting and to prevent the entry of air into the space between the bottom of the base and the roof of the vehicle for improved aerodynamics and noise reduction. In a preferred embodiment, the cargo carrier includes means for attaching the inverted cover to a utility trailer thereby allowing the cover to be towed behind a vehicle as a cargo carrier. In addition, either the cover or the base can be used separately on a vehicle roof.
