Generally speaking, buying a car as an investment is a bad idea. The vast majority of cars will only depreciate, so it's better to just buy a car because it's one that you like and does what you need it to. With that said, there are some cars that seem to be exceptions to the investment rule, and among them are highly limited-edition Porsches. Bring A Trailer recently sold a perfect example of this phenomenon: a 2023 Porsche 911 Sport Classic. In just three years, its value nearly doubled from new. It Went For Well Into The Six-Figure Range The winning bid on this Sport Classic, which was number 1,207 of 1,250 built, was $511,000. When the Sport Classic launched, it had an MSRP of $272,300, and this particular model had a final price of $283,240 with options, destination charge, and Gas Guzzler Tax.Bring A TrailerSo that's an increase in value of $227,760, which is a little less than $10,000 shy of the price of a new 911 GT3. That's also a gain of about $75,920 a year, or about $56 per mile, since the car has 4,071 miles on it.Of course, we're assuming the original buyer was able to get this Sport Classic without any markups. Back when these cars were new, some dealers were putting some insane markups on them. One dealer dared to add $250,000 on top of one, which would've topped the sale price of this example. Also, if you're curious, the options on this car include a Burmester sound system, surround view cameras, lane-change assist, Power Steering Plus, ambient lighting, puddle lights, power folding mirrors, and aluminum pedals.Bring A Trailer This Sale Wasn't A Fluke Looking at past 911 Sport Classic sales at Bring A Trailer, the half-million price point is pretty much on par for this Porsche. Two other grey examples sold for just under $500,000, and a blue one went for an astonishing $632,000. That one was the most expensive example the site ever sold. Part of that higher price was due to the Paint To Sample color, as well as a host of other special options such as lightweight glass and carbon ceramic brakes. Similar factors likely drove a Ruby Star Paint To Sample example to go for $552,000 last October. Even as far back as 2024, Sport Classics were selling for more than $400,000.It's not even the only special Porsche to bring big money. The even more recent 911 S/T was a sort of Sport Classic for the GT3. It used the 518-horsepower engine from the GT3 RS, but coupled to a six-speed manual. It was also the lightest example of the 992 911 generation. It had a base price of $290,000, and they regularly sell for more than $600,000 on Bring A Trailer.Bring A Trailer The Features That Make The Sport Classic So Special You've already seen that the Sport Classic was produced in very limited numbers, but that's only the tip of the ice burg for what makes it so collectible. For one thing, it has unique styling inspired by 911s throughout history. It has a ducktail spoiler that became a signature of early Carrera RS models. It has a unique hood that matches the subtle double-bubble-style roof, and it has retro graphics including stripes down the top and wordmark stripes on each side.Bring A TrailerThe wheels are also retro, inspired by the distinctive Fuchs wheels used on the earliest 911s. Porsche topped it all off with gold-finish badges.The interior features other retro design cues. The seats are finished in a dark tan leather with black-and-white Pepita fabric inserts. Natural-finish wood trim adorns the dashboard with another gold badge, and the gauge graphics are inspired by early Porsches.Bring A Trailer What really makes the Sport Classic something particularly unique is its powertrain. The car is based on the 911 Turbo S, but it has a few key changes that were never offered on the equivalent Turbo S. Those changes were all about increasing driving involvement, with the first one being the use of Porsche's 7-speed manual transmission. On top of that, Porsche made the Sport Classic rear-wheel drive.It's worth noting that the Turbo S is always the most powerful and fastest Porsche in a straight line, so reducing the number of drive wheels and ditching the dual-clutch transmission would make for a wild ride. At the time, the Turbo S made 572 horsepower and 553 pound-feet of torque.Porsche cut output a bit for this particular model, apparently to spare the transmission, but it likely also made it a little easier to handle. In the end, it made 543 hp and 442 lb-ft of torque, which still made it the most powerful manual 911 on the market at the time. It even tops today's most-powerful manual 911, the GT3 with 502 hp and just 331 lb-ft of torque.