The 10th-gen Ford Thunderbird was maybe the ultimate sleeper of the 1990s, sharing a range of engines with the Ford Mustang of its era, with an understated visual design that hid its true nature as a potent muscle car. 1994 introduced the 4.6-liter modular V8 to the lineup for 205 horsepower, while a supercharged 3.8-liter V6 produced 230 hp in the Super Coupe. Neither of these powerplants came close to being the car's most powerful engine, though.Before Ford pulled the plug on the 1990s version of the 'Bird, the brand had the Special Vehicle Engineering team hard at work on what should have been the hottest car of the decade. Essentially a supercharged version of the V8 model, the Cobra-inspired SVE Thunderbird could run circles around its siblings, and most Mustangs for that matter, but the mass market never got to enjoy this one. With only one model known to exist, it's as rare as a car can get while still technically existing. The Thunderbird SVE Shared Its Engine With The Mustang Mach III Bring a Trailer The 1997 Ford Thunderbird SVE never made it into the hands of the public and, if it was subjected to extensive track testing, that data was never made available. So we can't know exactly how quickly it would have cleared 60 mph or what kind of horsepower it was producing, but we know that the car packed the same supercharged engine as the Ford Mustang Mach III concept car, and, since the Thunderbird is mainly just a sleeper Mustang, we imagine the performance specs would have been in the same ballpark.The SVE Thunderbird didn't feature much in the way of mechanical upgrades. The car got some bigger exhaust tips and a set of 17-inch five-spoke Mustang Cobra R wheels, and you can spot an SVE Model at a glance by its cowl hood. But, outside of the supercharged engine, the SVE Bird's changes from the standard 1995 Thunderbird were mostly cosmetic.The car was largely pieced together from little bits of this and that, with headlights, door handles, and rear bumpers provided by the 1994–1995 models, while the front fascias and body cladding come from the 1996–1997 models. SVE Built Four Thunderbirds, And Destroyed Three Of Them Bring a TrailerAs the story goes, Ford SVE was looking to build a high performance model of the 10th-gen Thunderbird that would prove to be a sort of greatest hits collection of everything cool about Ford muscle cars in the 1990s. SVE borrowed odds and ends from various Mustangs and Thunderbirds to produce what should have been the greatest sleeper car ever built.The project came to a sudden halt when Ford scrapped the entire Thunderbird line, along with its fellow Mustang-brother, the Mercury Cougar. By this point, SVE had built four prototypes. Three of these prototypes would be destroyed, while the fourth, at last report, is still in the hands of a private owner. The final 10th-gen Thunderbird rolled off the Lorain, Ohio assembly line with a sign on its decklid reading "That's All Folks." Spotting The Remaining SVE Thunderbird Is Like Seeing A UFO Today, the car has reached mythic status. The only video we can find of the SVE Thunderbird comes from the 1997 Hot Rod Power Tour, where it was captured by YouTuber @SilverDuratecZX3.The grainy, 2007-quality video only reinforces the SVE 'Bird as the automotive equivalent of a cryptid, like the Mothman or something. This video is like a Bigfoot sighting, complete with skeptics in the comments doubting that it's the real deal. A 1997 Thunderbird Isn't A Bad Consolation Prize Bring a Trailer Since there's only one SVE Thunderbird on the planet, and the owner doesn't seem interested in selling it off, a 1997 Thunderbird with a 4.6-liter V8 under the hood will have to do. And, of course, there's nothing saying you can't supercharge it yourself.The mid to late-1990s model Thunderbirds were decent sellers, moving 112,302 units in 1996 and 85,276 units in 1997. Across nine model years, from 1989 to 1997, the 10th-gen Thunderbird sold 960,624 units in total. Had the car been allowed to fish out the decade before its retirement, we have no doubt that those sales numbers would have easily topped a cool million.If you ask us, the 10th-gen Thunderbird looks like a roaring success. Internally, it was a different story. Ford didn't like the fact that the car cost $900 more per unit than planned, or that it was 250 lbs over its targeted curb weight. In fact, the car's poor initial reception among Ford's top brass played a part in the MN12 Thunderbird program's manager, Anthony S. Kuchta, parting ways with the brand shortly after the introduction of the 1989 Thunderbird. Mid-90s Thunderbirds Can Be Had For A Song Bring a Trailer We can get an idea of what a 1990s Thunderbird will cost you in 2026 by taking a look at recent auction data for 1997 model 'Birds.These numbers are based on four successful auctions over the last 12 months. It's not unusual to see the cars listed well above these numbers, but those listings are rarely successful. A 1997 Thunderbird LX failed to find a buyer on Mecum last May, despite putting just 561 miles on the odometer, because the asking price of $14,000 was simply too high for anyone in the market.At the low end, a 49,000-mile LX sold in Sparta, Tennessee in February for $5,700, through auction. So these prices aren't necessarily for models that are past their prime. With under 50,000 miles on the original engine and transmission, this car could easily go another quarter million miles before its first real breakdown. What Does It Cost To Supercharge A Thunderbird? Bring A TrailerIt's a good thing '90s Thunderbirds are selling for cheap, because a brand-new supercharger for its 4.6-liter modular V8 is likely to cost you around half as much as the car itself. Super Coupe Performance Parts currently has a Tork Tech Supercharger in stock for the 1994-1997 Thunderbird, promising to deliver up to 400 rear wheel horsepower, with some tuners getting up to 600 RWHP and up.Once you've added in all the various parts you'll need to supercharge your Thunderbird, and hired a pro to handle the upgrades for you, if you're not confident in your DIY tuning skills, you may find that the actual car makes up less than a third of the project's total cost. But, that's the only way you're ever going to get something like an SVE Thunderbird of your own, because the real deal is as rare as it gets.The closest car we've seen to a production SVE Thunderbird would probably be the 2003 SVT Mustang Cobra, delivering 290 hp from a 4.6-liter modular V8 engine, and clearing 60 mph in just under five seconds. The Cobra isn't unreasonably expensive, either, commanding an average auction price of around $40,000, with some sales closing as low as $11,000.Not counting a 175,067-mile 10th Anniversary Edition, the most recent successful US sale for an SVT Cobra was a January auction on Bring a Trailer, with a 25,000-mile closing at $36,000. That's more than you'd likely spend on a new Nissan these days, but, given how a project car can spiral out of control, that might wind up being cheaper than buying a Thunderbird and building an SVE of your own.