A rear lift gate can be hingedly coupled to a truck cap body and movable between a lowered closed position and a raised open position. The rear lift gate can include a lower margin having a convex shape generally corresponding to an outward or rearward convex upper margin of the tailgate. The rear lift gate can further include a seal strip mounted to an interior side of the lower margin of the rear lift gate. The convex lower margin of the rear lift gate can overlay the convex upper margin of the exterior side of the tailgate with the seal strip of the interior side of the lower margin of the rear lift gate sealing against the exterior side of the convex upper margin of the tailgate when the rear lift gate is in the lowered closed position.