By 1970, the Ford Mustang had become one of the most popular cars in America, however, sales had begun to slow. The Mustang turned a tidy profit for the Blue Oval, and to improve sales Ford began offering all sorts of national and regional option packages, like the Twister package or the California Special.

One of the rarest and least-documented Mustang variants of all is the Sidewinder Special, of which very little is known but much is rumored. eBay item number 231073926970 is a Grabber Orange Sidewinder Special, one of just seven known to still exist, and it’s for sale right now.

There is plenty of controversy over what the Sidewinder Special package was or wasn’t. Just around 40 examples were ever built, and all came from Ford’s Dearborn factory in Sportroof style. The engine was a 351C/4V, and a special sticker package differentiated it from plain-jane Mustangs. Of the 40 built, just seven have been accounted for to date.

While it is fairly certain this was a Ford-sponsored package, and not just a random dealer gimmick, it is hard to be certain. The Sidewinder Specials were all sold at either Nebraska or Iowa dealerships, only a few people appear to have held on to them. It’s value is anybody’s guess, though this well-restored example has to be worth some serious cash to the right buyer. Is this what you need to complete you’re Mustang collection?