kind of an old post but.. the mustang II/pinto racks pivots are 24.5" apart. flaming river sells a 5" narrowed rack that makes the pivots 19.5" wide. the distance between the stock toyota lowers is roughly 19.25". it is the closest thing that i have found (i've measured a ton of cars in the scrapyards, and none came close), but it is kind of pricey for a manual rack. here is the link:
http://www.flamingriver.com/index.cfm/page/ptype=product/product_id=238/category_id=66/home_id=63/mode=prod/prd238.htm