A sliding window assembly for a vehicle comprises a first fixed panel and a second fixed panel spaced from the first fixed panel. A sliding panel is movable relative to the fixed panels. A rail is coupled to the fixed panels. The rail has a channel portion for receiving the sliding panel and an attachment portion extending from the channel portion. The attachment portion has an interior surface. The sliding window assembly further comprises an elongated member that couples the rail to the fixed panels. The elongated member partially encapsulates the rail with a portion of the interior surface of the attachment portion free of the elongated member to present an exposed bonding surface. The exposed bonding surface allows the rail to be bonded to the flange of the vehicle for mounting the sliding window assembly to the vehicle.