Sleepers: 10 Cars That Are Way Faster Than They Look

For the majority of performance cars, looking good is just as important as being fast. After all, buyers who are willing to spend significant premiums on the most powerful cars are usually keen on showing their new toy off as much as possible. Whether it's a body kit, racing wheels, or prominent badging, it's usually pretty easy to spot a performance car. However, that's not always the case.

For a variety of reasons, some manufacturers choose to hide their most powerful engines in cars with nondescript styling. They're easy to pass in the street or drive by on the highway — that is, until you see one take off and leave everyone else in the dust. These cars are commonly referred to as sleepers, and for some enthusiasts, they're an ideal combination. Thundering acceleration that's only a push of the throttle away, but without the hassle of daily driving a flashy performance car. These sleepers are leaders from both domestic and foreign manufacturers.

Although Volvo is most famous for its focus on safety and sensibility, it's been known to release the odd under-the-radar performance car. The S60 R is one such car — it's essentially a 300-horsepower sports sedan that looks no different at first glance from the standard S60. Testing by Autocar revealed a 0-60 mph time of 6.3 seconds, with its top speed matching that of its chief German rivals, at just over 155 mph.

A standard six-speed manual transmission won the S60 R further enthusiast points, although a five-speed auto 'box was also available. Power was sent to all wheels while the brand's Continuously Control Chassis Concept (Four C) system ensured sharp handling across a variety of road surfaces.

Despite its performance credentials, the S60 R never gained much attention in America. However, that has meant that used prices have remained temptingly cheap. It's one of the fastest cars you can buy for less than $10,000, although it's worth noting that the added electronics compared to the standard S60 means that maintenance won't be quite as cheap.

At first glance, the Chevrolet SS is just another four-door sedan with a Bow Tie badge. It's an obscure one, too, with less than 13,000 examples produced across its lifespan. However, look across auction sites and you'll find the resale value of the car hovering right around its original $44,500 asking price. The reason why can be found under the hood: a 6.2L LS3 V8 making 415 horsepower. Not exactly what you might expect to find in the average Chevy sedan.

That's because this was something far from the rental car image most people associated with its looks. It was a proper family-hauling muscle car, hailing not from America but instead from GM's Australian subsidiary, Holden. Australians had continued building muscle cars long after American manufacturers had given up, with the Chevy SS being a rebadged variant of the long-running Holden Commodore.

Buyers who overlooked the SS in its original production run between 2014 and 2017 have missed their chance, as the factory that made the car was closed the same year SS production ended. The Holden brand itself was axed in 2021 as GM pulled out of the right-hand drive market, leaving virtually zero chance for an Aussie-built successor to arrive. That's exactly why collectors are willing to pay increasingly high premiums for this seemingly ordinary-looking Chevy.

The BMW M5 has long been considered a benchmark in the performance sedan segment, but one of its closest rivals comes from within the 5 Series range. The M550i xDrive is a step below the full-fat M5 in the lineup, but it offers a lot of the same charms and can be had for substantially less. It's also less obviously a performance sedan than the M5, with only some new wheels and subtle exterior trim tweaks differentiating it from lesser 5 Series models.

Despite that, it packs roughly 90% of the power of the M5 and boasts similarly sharp handling. Not quite as sharp as the top-spec car, mind: The M550i xDrive is set up more as a powerful daily driver than a world-beating track sedan, and so it's a little comfier on rougher roads. The cabin is also handsomely equipped, with the optional Nappa leather adding an extra touch of luxury. It might be a great sleeper sedan, but it comes at a cost. SlashGear's fully optioned test car's MSRP reached more than $93,000, making it one of the priciest cars on this list.

The Pontiac G8 GXP was built to the same recipe as its successor, the Chevrolet SS. Take a Holden muscle car from Australia, import it to America, and slap a new badge on it. The Aussie car in question was the LS3-powered Commodore, which made over 400 horsepower and followed the trusty front engine, rear drive formula that muscle cars have relied on since their inception.

In an early road test, Car and Driver referred to the G8 GXP as a "four-door Corvette," with its impressive power and handling made even better by the fact that it could be picked up for just $40,000. However, unlike the Corvette, it lacked any distinctive styling, and this undoubtedly hurt its sales chances.

Pontiac had struggled with its image for years beforehand, but the G8 GXP proved that it could still sell proper performance cars, even if they weren't built in America. However, it wasn't enough to save the brand, and by 2009, GM had announced it would be retiring Pontiac altogether. With it, buyers lost one of the brand's last genuinely impressive cars. Holden itself would suffer the same fate less than a decade later, with Australian production ceasing in 2017.

[Featured image by IFCAR via Wikimedia Commons | Cropped and scaled | Public Domain]

Built both as a sedan and a wagon, the second-gen Audi RS6 looked much like any other Audi executive car in passing. However, under the hood sat the V10 engine from the Lamborghini Gallardo, enhanced with twin turbochargers. That pushed its power output up to 572 horsepower, with its Quattro all-wheel drive system ensuring all those horses were delivered to the asphalt as efficiently as possible. The sprint from 0-62 mph took just 4.6 seconds, while a 155 mph limiter ensured the car stuck to the German gentleman's agreement. Without it, the car could reportedly reach more than 200 mph.

Unlike the modern Audi RS6 which features unique styling to reinforce its supercar-rivaling performance, this generation of the RS6 was largely anonymous both inside and out. That did, however, make it a surprisingly practical family car, with plenty of room in the back for passengers and their luggage. The car was never sold in the U.S., but with an asking price in Europe equivalent to more than $100,000, it's safe to assume it would never have been a bestseller for Audi anyway. However, for well-heeled enthusiasts looking for the ultimate sleeper, few other cars come close.