You pull up to the lights in your sports car. It’s a rumbly, grumbly old muscle car with a manual transmission in the middle and a confident piece of meat in the driver’s seat. You’re almost certain you can outrun the sober-looking sedan in the next lane over. But when the light turns green, you watch a set of taillights walk away. That’s the impact of a proper sleeper car.It’s performance where you least suspect it: in a four-door family car with a usable trunk and understated styling. Want one? Well, it’s not a new concept. The early 2000s hosted many oft-overlooked sleepers with Herculean horsepower reserves. And, as far as picking smile-inducing power over garish styling goes, this short-lived American sedan might be one of the best examples of all. You Might Not Want To Wake A Sleeper ChevroletSleeper. The term doesn’t exactly invoke fear in the same way that muscle car, halo car, or hypercar does. There’s a good reason for that. A sleeper is an under-the-radar performance car. Something you might expect to make the school run or pull up to the Pee Wee game, positively brimming with pungent football pads. That’s part of the magic. Under normal conditions, a sleeper car is no noisier or more disruptive than your typical family sedan. Unlike its sedate counterparts, though, a sleeper packs a powerful engine and handling dynamics. It lives in the space between a razor-sharp sports car and a grocery-getter. What Makes A Good Sleeper Car? Cadillac Bleeding-edge performance variants of luxury cars aren’t a new thing. The BMW M5, for instance, has been shaking up suburbia and rattling Wall Street’s windows for decades. In earlier iterations of the BMW super executive sedan, like the E34 M5, it was difficult to discern from the more sedate V8-powered 5 Series cars.Audi Today, however, swivel-eyed super sedans like the Audi RS7, Cadillac CT5-V Blackwing, and yes, the BMW M5, are often lower, wider, and dripping with carbon fiber when compared to their less premium cousins. But truly understated sleepers, especially those of the eight-cylinder kind, are on the endangered species list. That said, a look back at the sleepers of 10, even 20 years ago, tells a different story. Like this hot rod in a police uniform from the Ford Motor Company’s now extinct Mercury brand. The Third-Gen Mercury Marauder: A Super-Powered Sleeper Ford Motor Company Chances are, if you live in the United States, you’ve seen a fourth-generation Ford Crown Victoria, Mercury Grand Marquis, or a Lincoln Town Car in the last few days. Need a little reminder? The Panther chassis, Ford sedan’s familiar shape, was the most popular police car (by a wide margin) in the country at the start of the 2000s. It was also a favorite among taxi cab programs like New York’s Yellow Cab service.Bring a Trailer In the spicier police models, the Ford Crown Victoria sported a 4.6-liter V8 with up to 250 horsepower. But the Panther platform wasn’t done there. For 2003, the Ford Motor Company and Mercury rolled out the Marauder, and, as the name suggests, it was an unapologetic take on the service-oriented sedan. After all, when you name a family sedan after murderous pillagers, it simply must rock. 302 American Ponies Bring a Trailer Under the hood, the 2003 and 2004 Mercury Marauder packed a 4.6-liter, dual-overhead cam V8. Nothing too strange there; the Crown Vics and Grand Marquis of the world displaced the same. But in the Marauder, that engine produced 302 horsepower and 318 pound-feet of torque.The bump in power is courtesy of touches like a dual exhaust system and a Jack Roush-sourced 80-mm intake, taking the 4.6 well beyond that of your typical Crown Victoria. That’s more muscle than you’d get in a similarly aged SN-95 Ford Mustang GT. So much for acting like a taxi cab, too. Cop Car Looks, Hot Rod Performance Bring a Trailer In addition to the more muscular 4.6-liter V8, the Marauder’s in-corner manners benefit from a set of nitrogen-filled shocks, a new frame, stouter crossmembers, and straight-as-an-arrow side rails. The complement of handling upgrades keeps things taut and composed compared to the sailing-ship ride of other Panther platform cars. Of course, with a properly portly 4,282-pound curb weight, the Marauder is more muscle car than it is dainty sports sedan. Doubt its muscle car credentials? Just take a quick look at the motorsport-esque gauges and remove all second-guessing. From the outside, though, it looks like something that might stalk motorists for speeding in a school zone. An Affordable American (Canadian) Sleeper Sedan Bring a Trailer Given all the gritty crime shows in which the Panther-platform cars have made an appearance, you’d think the big, no-frills sedan would be as American as Harley-Davidson. Not quite, though. For its two years in production, the Marauder had a home in Ford’s Ontario, Canada, plant. Scandalous, right? It’s not that unusual, really. Dodge produced its muscle-bound Charger and Challenger in Canada right up until discontinuation. Unlike prescription medication, though, you don’t have to journey across the border to get one for cheap. Mercury Marauder Average Pricing Bring a Trailer As of this writing, last year’s average sales price for a well-maintained and looked-after Mercury Marauder was around $20,506. However, shrewd shoppers can find them for around $12,000 – if they know where to look. For instance, a 2003 model with 89,000 miles on the clock sold in a no-reserve Bring a Trailer auction for just $12,250 last December. You know what else is great about affordability? It could mean that a meager budget still has enough meat left over to turn to the aftermarket. With bolt-on aftermarket parts like a cold air intake, an aftermarket exhaust system, and a tune, the Marauder has the potential to be a serious street rod. Oh, and can anyone say supercharger? So, Should You Buy One? Ford Motor Company Considering only 11,052 Mercury Marauders rolled off the assembly line during its two-year run, this is one rare sleeper. That said, even with 302 horsepower, the Marauder is a bit underpowered for its size and weight. It’s also not the only early 2000s sleeper car out there.Interior shot of a 2003 Mercury Marauder showing front seatsA couple of years after the Marauder drove off into the sunset, for example, the Chevrolet Impala SS coaxed 303 horsepower out of a 5.3-liter V8. Not bad for a big, comfortable family sedan that blends in with traffic seamlessly. Far from it. That said, if you’ve ever wondered what injecting bull hormones into a taxi looks like, the Marauder answers your question.Sources: Ford Motor Company, Bring a Trailer, Edmunds, Classic.com