Chrysler products featured tremendous interchangeability among makes and models, but the parts swapping didn’t always work out to perfection.

Not long ago here at Mac’s Motor City Garage, we told the story of the 1970 Plymouth Duster, which became a surprise runaway hit for the Chrysler Corporation. (See our feature here.) It was such a big seller, in fact, that Dodge division chief Bob McCurry (inventor of the rebate) was soon clamoring for a piece of the action. His wish was granted, and a Dodge version of the Duster to be called the Dart Demon was rushed into production for 1971.

It was simple enough to do. Platform sharing and interchangeability among the brands were traditions at the Chrysler Corporation that dated back to the founding of the company. To create the Demon, the Dart front doghouse was combined with the cab and rear half of the Valiant Duster body shell. The Dodge Dart and Plymouth Valiant shared a common Chrysler A-body platform and all the pieces basically bolted up. However: While the Dodge and Plymouth packages were similar, they weren’t identical, especially in their styling details.

For example, Valiant wheel openings have a pronounced flare, often finished with a chrome garnish. But on the Dart, the wheel opening lip and trim molding are recessed into the fender. And so it is that the Dart Demon—a Dodge in the front and a Plymouth in the back, if you will—has two different styles of wheel openings front and rear.

It’s certainly not a big deal. A professional stylist or a body-and-paint technician will definitely notice it. A sharp-eyed enthusiast will probably see it as well, but there’s little indication that civilian car buyers ever spotted the discrepancy. It sure didn’t bother them. Like the Duster, its sister the Demon was a solid seller for the Chrysler Corporation, despite the “wrong” wheel openings.

Veteran Chrysler stylist and automotive historian Jeff Godshall made reference to the dueling wheel-opening schemes in the April 1999 isssue of Collectible Automobile. There, he noted that managers and stylists were totally aware of the issue, naturally, but they decided not to care. At Chrysler there were bigger things to worry about, and the tooling was never changed. With its mismatched wheel lips, the Demon was renamed the Dart Sport in 1973 and remained in production through 1976.

1976 Dodge Dart Sport

Plymouth didn’t escape the issue, either. When Dodge received its own version of the Duster in 1971, Plymouth in turn got a variant of the Swinger, the pillarless hardtop version of the Dart. Since the Plymouth Scamp (1974 shown below) was a Plymouth in front and Dodge in the back, the wheel opening mismatch was reversed. And here, if anything the difference is even more noticeable. You may not see it, but once you see it, you’ll never unsee it. (Sorry, OCD sufferers.) Like the Demon/Dart Sport, the Scamp remained in production through 1976.