Image Credit: Desert Private Collection.The 1955 Chrysler C-300 is one of the most important early American performance cars, yet one body style is conspicuously absent from the official history books. Chrysler sold the C-300 as a hardtop, which makes the black convertible featured by the Motorcity YouTube channel especially difficult to explain.The video points out that the then-owner claimed the car could be one of just two or three convertibles allegedly built for the 1955 auto show circuit. There is a major problem with that story, however, because no surviving factory documentation has surfaced to prove Chrysler actually produced any C-300 convertibles that year.That uncertainty has followed the car through multiple auction appearances, including a 2021 Palm Springs auction where bidding reportedly reached $35,000 without meeting the reserve. It later appeared at Mecum and has now resurfaced for sale again, this time advertised on Craigslist for $39,000 by California-based Desert Private Collection.AdvertisementAdvertisementWhat remains is a fascinating classic that looks convincing, carries much of the correct hardware, and may have an unusual history behind it. Whether it is a lost factory show car, a later conversion, or an expertly assembled tribute remains the question hanging over the entire car.Chrysler Never Cataloged A 1955 C-300 ConvertibleThe C-300 arrived in 1955 with a 331-cubic-inch FirePower Hemi V8 producing a headline-grabbing 300 horsepower. Chrysler built 1,725 examples during that first model year, and the accepted production record identifies them as hardtops.That makes any 1955 C-300 convertible immediately controversial. A genuine factory-built example would represent an extraordinary discovery, especially if it could be documented as a show car or special-order vehicle.The original seller apparently had a letter from Chrysler stating that the company could neither confirm this particular car nor verify that any C-300 convertibles were built in 1955. That wording leaves room for speculation, although it does not provide the kind of proof collectors typically require before assigning six-figure values.The Car Has Some Intriguing DetailsImage Credit: Desert Private Collection.One of the strongest arguments presented in favor of the car is its X-frame construction, which would be the frame type Chrysler used for convertibles, where additional structural reinforcement was needed to compensate for the missing roof.AdvertisementAdvertisementThe car also carries a 331 Hemi V8, and its engine number has reportedly been described as falling within the expected range for a period-correct C-300. Visually, it also presents itself convincingly with black paint, a tan interior, wire wheels, period chrome, and a power-operated convertible top.Its current Craigslist advertisement lists 22,645 miles, an automatic transmission, power seats, and the 300-horsepower Hemi. The seller is asking $39,000, which is far removed from the kind of money a fully authenticated factory prototype could theoretically command.A Racing Connection Makes The Story Even StrangerPart of the car's backstory involves Carl Kiekhaefer, founder of Mercury Outboard Motors and a major figure in early NASCAR competition. His Chrysler-backed racing operation famously used C-300s with considerable success during the 1950s.The theory attached to this convertible is that Kiekhaefer may have been involved in commissioning a small number of special cars for promotional or show purposes. It is a compelling piece of automotive folklore, yet no conclusive factory paperwork, period photographs, or build records have emerged to substantiate it.AdvertisementAdvertisementThat missing evidence is important because the difference between a genuine factory one-off and a later custom conversion can be enormous in the collector market. Without documentation, buyers are effectively valuing the car on what it physically is rather than what its story claims it might be.The Mystery May Be The Best PartImage Credit: Desert Private Collection.Even if this Chrysler turns out to be a later conversion, it remains an appealing interpretation of a car Chrysler arguably should have offered. The combination of a 331 Hemi, elegant 1950s styling, and open-top bodywork creates a compelling grand-touring package.The unanswered history is what makes it difficult to ignore, and until stronger documentation surfaces, this supposed 1955 C-300 convertible will remain somewhere between genuine factory oddity and exceptionally convincing custom build.Do you think this Chrysler could really be a forgotten factory show car? Would you pay $39,000 for it even without definitive provenance? Let us know in the comments.AdvertisementAdvertisementIf you want more stories like this, follow Guessing Headlights on Yahoo so you don't miss what's coming next.