1975 GMC Trucks Rally Wagon Sales Folder. Rally...with Big Comfort and Performance. Thre Great Crowd Pleaser Returns. Fresh from another successful engagement in the cities, suburbs, and campgrounds of America, the Rally Wagon and STX model return by popular demand with features bound to please the most discriminating traveler. Goes on to highlight other features, safety features, and power train options. ADV 75-8 (8-74)