With Mecum Kissimmee, it’s a good time to take a closer look at the factory options that turned performance machines into auction record holders.
When these cars were new, they weren’t envisioned as futuristic collectibles. They were production vehicles that you could go to a dealership and order by checking the boxes on the form. Many of these options were left out simply because the average buyer didn’t feel the need for extra performance for the added cost, and no one thought about how those decisions would make a difference decades later.
The following is not an exhaustive list. This is a cross-section of factory options and vehicles, the size of which we can actually find source photos. Some rare configurations do not have usable images available, so they are not represented here.
Decades later, those same choices are why these cars now sit at the top of the collector market.
1971 Plymouth Hemi ‘Cuda Convertible
Photo courtesy of Mecum Auctions, Inc
Auction Prices: Multi-millions
Among American muscle cars, few factory option combinations have proven more valuable than the pairing of 426 Hemi power and a convertible body, especially at the end of the muscle car era.
For 1971, the last year of Hemi ‘Cuda production, Plymouth built just 12 Hemi ‘Cuda convertibles. That extraordinarily low production figure is the primary driver of the model’s value today.
Survival is extremely limited, and documentation is critical. Cars that retain their original matching numbers 426/425 HP Hemi engines, factory drivetrains, and certified build data occupy the top tier of the collector market. Differences such as automatic versus manual transmission, Excel packages, and production sequence can have a measurable effect on price in a small number of known examples.
A documented 1971 Hemi ‘Cuda convertible currently offered at Mecum Kissimmee 2026 shows how a single factory option—a Hemi engine mated to a convertible body—now places these cars among the most valuable American muscle cars ever built.
Like the other vehicles featured here, the Hemi ‘Cuda Convertible’s status is not the result of racing success or aftermarket modifications. Its value is defined by a factory-approved option that was technically available, rarely chosen, and never repeated.
More details.
1969 Chevrolet COPO Camaro ZL1
A wide angle front view of a 1969 Chevrolet Camaro COPO shown for illustration purposes at a local car show. Engine specifications cannot be confirmed from the image. Image credit: Gestalt Imagery / Shutterstock
Auction Price: ~$1.09 million
In the late 1960s, General Motors officially limited Camaro engine displacement to 400 cubic inches. Traders found a solution through the Central Office Production Order (COPO) system, which allows special-purpose vehicles to bypass standard restrictions.
Through COPO, select Camaros can be ordered with the 427-cubic-inch V8. Most received iron-block engines, but only the ’69 was fitted with the all-aluminum ZL1, an engine derived from Chevrolet’s Can-Am racing program. The ZL1 dramatically reduced weight while delivering immense power, making it one of the most extreme factory engine options ever installed on a road car.
That simple engine choice elevates COPO ZL1 Camaros documented today into seven-figure territory.
1970 Pontiac GTO Judge Convertible
Photo courtesy of Mecum Auctions, Inc
Auction Price: ~$1.1 million
The Judge was already a bold performance and appearance package, but combining it with a convertible body style created one of the rare factory GTO configurations offered by Pontiac.
Only 168 GTO Judge convertibles were built for the 1970 model year. With no foreign engine distinguishing these cars mechanically, the Judge package itself was a defining factory option, and combining it with an open body proved unpopular when new.
That low take rate drives their value today.
1970 Dodge Challenger R/T Convertible with 426 Hemi
Photo courtesy of Mecum Auctions, Inc
Auction Price: ~$1.45 million
Dodge produced the 963 Challenger R/T Convertible in 1970. Of those, only five were ordered with the 426 Street Hemi and four-speed manual transmission.
The Hemi was a fully factory-approved engine option, but its high cost and demanding nature discouraged most buyers, especially of the convertible. Survivorship is exceptionally low, and the rarity of that option combination pushes these cars into million dollar territory.
1970 Plymouth Superbird with 426 Hemi
Photo courtesy of Mecum Auctions, Inc
Auction Price: ~$1.65 million
Built to homologate aerodynamic components for NASCAR competition, the Superbird was extreme even by muscle-car standards. About 1,920 were produced, with most 440 equipped with the Magnum V8.
Only about 135-170 were ordered with the optional 426 Hemi, an expensive upgrade selected by few buyers at the time. Today, that single factory engine option often separates the six-figure Superbirds from the seven-figure examples.
1969 Dodge Charger Daytona with 426 Hemi
A close-up of a 1969 Dodge Daytona Charger 426 Hemi Wing on display at the Concours d’Elegance of America car show at The Inn in St. John’s. Image credit: Steve Lagreca / Shutterstock
Auction Price: ~$3.0 million+
Dodge built 503 Charger Daytonas, the majority powered by the 440 Magnum. Only about 70 left the factory with the 426 Hemi, making them one of the rarest American muscle cars ever produced.
The combination of radical aerodynamics and the Hemi engine created an impressive race car and one of the most valuable factory option packages of the era.
Mercedes-Benz 300 SL Gullwing with factory alloy body
A Mercedes-Benz 300 SL Gullwing is shown for illustration purposes. The factory alloy-body option, offered in minimal numbers, is discussed in this feature. Image credit: Art Konovalov / Shutterstock
Auction Prices: Multiple sales in the multi-million-dollar range
When the Mercedes-Benz 300 SL debuted in 1954, it was already revolutionary. However a small number of buyers were allowed to order the Leichtmetallausführung, or light metal version.
This factory option replaced the standard steel body panels with aluminum ones and added competition-oriented components. This option carried a substantial price premium when new, and fewer than 30 alloy Gullwings were produced.
Today, documented factory alloy examples sell for millions more than standard steel-bodied cars.
Chevrolet Corvette L88 (1967-1969)
Photo courtesy of Mecum Auctions, Inc
Auction prices: Can exceed $3 million
The L88 was one of the most extreme factory engine options offered on a production Corvette. Introduced in 1967 and available through 1969, this option extended to the final years of the C2 and the early C3 generation, with the engine itself—rather than the body style—being the defining factor.
Officially rated at 430 horsepower, the aluminum-head 427-cubic-inch V-8 was deliberately underrated. Real-world output was significantly higher, but Chevrolet tied the L88 to restrictive order requirements that ensured only informed buyers selected it.
Opting for the RPO L88 automatically bundles heavy-duty suspension and cooling components while ditching the usual comfort features like the radio and heater. The result was a Corvette that prioritized performance over utility, reinforcing the engine’s competition-focused intent.
Originality and documentation are important to the price, as the purpose-built nature of the L88 makes correct components and factory certification especially important. Late-C2 or early-C3, well-documented examples consistently remain at the top of the Corvette market.
Like the other vehicles featured here, the L88 Corvette’s status is defined by a factory-approved option that was technically available, rarely optioned, and never intended for casual ownership. That single-engine decision now puts these cars firmly in multi-million-dollar territory.
Chevrolet Corvette L89 (1967-1968)
Photo courtesy of Mecum Auctions, Inc
The L89 was a factory option that spanned two Corvette generations, the last year of the C2 and the first year of the C3. Instead of being tied to a single body style, the option itself was the defining factor.
The RPO L89 combines Chevrolet’s 427-cubic-inch big-block with aluminum cylinder heads, reducing weight while preserving street utility. It can be ordered with many 427 variants, making it a flexible but rarely selected performance upgrade.
In total, fewer than 850 Corvettes are believed to have been equipped with the L89 option in both model years. While not every example commands seven figures, the most original, well-documented cars — aside from Generations — have passed the million-dollar mark at auction.
Like the other vehicles featured here, it’s the factory-approved options, not just the body style, that define long-term value.
Chevrolet Corvette ZR2 (1971)
Photo courtesy of Mecum Auctions, Inc
Auction prices: Near or over $1 million
Offered for just one year, the RPO ZR2 was a factory competition package built around the high-revving LT1 small-block V8. It added heavy-duty suspension, upgraded cooling, racing-focused driveline components, and deleted the usual comfort features.
Only 12 ZR2 Corvettes were built, making it one of the rarest factory Corvette options.
Options to change everything
Plymouth Superbird Convertible. While not featured in this article, it earns a spot here for sheer cool factor. Image credit: Sergey Kohl / Shutterstock
None of these car accidents collected million dollars. In each case, the jump in price goes back to the factory-approved options that were available Rarely chosen.
These were not dealer modifications or one-off prototypes. They were decisions made on order forms, often dismissed as unnecessary at the time. Decades later, those decisions define the top of the collector market.
Sometimes, the most valuable performance upgrade isn’t horsepower alone—it’s the option that almost no one orders.
