In the '80s and '90s, there was one type of car that seemed at odds with what was going on in the rest of the world. This was an era when people in expensive suits walked around with cell phones the size of house bricks, while MTV blared with music videos that seemed to be in multiple hues of neon. The car to have for any self-respecting stock-broking chancer (or a basketball superstar) was a Ferrari Testarossa or 512TR, or perhaps a Lamborghini Countach. In short, this was a time of excess and bling, showing the world that you had made it. But this is also a period when the sleeper car started to become popular, a vehicle that was the opposite of what was going on in the rest of the world.These cars, epitomized by the BMW M5, were expensive, powerful and finely-tuned, but the sedan bodywork gave little away about the performance within. Think of a sleeper as the perfect car for the company CEO to drive to a meeting to discuss workforce lay-offs, or for the lottery winner who didn't want the extended family to know exactly how much they won. One American manufacturer stepped into the sleeper game almost by accident in the '90s, with a model that was born out of a mix of desperation and a raid of the parts bin. Maybe it shouldn't have even existed in the first place, but we are glad that this Corvette-powered sleeper did. The '94-96 Chevy Impala SS Is A Stealthy '90s Sleeper Sedan via Bring A Trailer The Chevrolet Impala could do no wrong in the '50s and '60s. The car was a glitzy jukebox on wheels in the late '50s, in the form of the 1958 Chevrolet Bel Air Impala Convertible, before becoming the boxy darling of the early muscle-car days. In the early '60s, Chevy introduced the Super Sport, or SS, performance package for the Impala, before making it a standalone production model in 1964, packing a 409-cubic-inch (6.7-liter) big-block. Of course, this muscle car party came to an abrupt end in the early '70s, with emissions regulations and oil prices arriving to switch on the lights and tell everyone to go home. The SS badge slowly died out, and by the sixth generation, the Impala itself had turned into the kind of boxy sedan that cops would use for stakeouts in '80s movies. The Impala SS Still Loomed Large In Muscle Car Folklore The public hadn't forgotten the Impala SS, however, but GM didn't really have a model that could do it justice. That is, until the new Caprice was launched in 1991. The 214.1-inch-long Caprice is a big car, and its low-hanging wheel arches made it look bigger and heavier than it was. Then there was chrome accenting everywhere, highlighting the bulbous shape – if we were being kind, we could almost say the Caprice was a bit too modern-looking for its own good – and the general appearance was chief of police, or retired lawyer, rather than city hotshot. The Caprice Was An Almost-There Car Via: Bring a Trailer There was nothing fundamentally wrong with the Caprice, which was built on the GM B-body platform; It just seemed to have a hint of '80s opulence at a time when people were more interested in cool new music videos and brooding Arnold Schwarzenegger films. Chevy must have been wondering what to do, but out of this tragedy came an opportunity. This accomplished yet flawed land yacht would be the unlikely basis for the new Impala SS. Looking back, it sounds a bit bonkers, but the plan actually worked. An Impala SS Concept Was Quickly Created In Time For SEMA A skunkworks team knocked up a concept for the new SS that would be shown at the 1992 SEMA show. The aesthetic changes were minimal but devastatingly effective. Those droopy rear wheel openings were opened up, and the car received a BMW-esque Hofmeister-Kink. Suddenly, the Caprice, or rather the Impala, looked more comfortable in its own skin, and the whole shape was more balanced and less rear-heavy. The finishing touch was a simple grille and a trunk spoiler, giving the new Impala a moody presence that could only really be matched by Robocop's Ford Taurus – especially for the 1994 SSs, which were only available in black with a gray interior. All GM needed now was an engine. The Chevy Impala SS Arrived Packing Corvette Power via Bring A TrailerWhen the production version of the Impala SS arrived, it differed little from the concept. The Caprice was popular with the police, so GM had a ready-made performance set-up for the SS. The car used the Caprice’s 9C1 police package, which had a raft of upgrades, including a more capable suspension, a transmission cooler, an improved cooling system, dual exhausts, and larger disc brakes behind the 17-inch alloy wheels. Usefully, there was also a limited-slip rear differential that was standard. None of these go-faster bits were wasted on a 180-horsepower 5.7-liter small-block V8. The Impala Looked To The Corvette For A Suitable Powerplant The Impala SS borrowed GM’s 5.7-liter LT1 V8 from the Corvette and Camaro, albeit with iron cylinder heads instead of aluminum. There were also two-bolt main bearing caps (instead of four) and a different camshaft for torque rather than high-end power. The result for the SS is 260 horsepower and a chunky 330 lb-ft of torque. Even though the Impala is just about as heavy as you would expect such a giant car to be (weighing in at 4,300 pounds) it is no slouch, even by today's standards. This levitathan of a car will hit 60 mph in 6.5 seconds and cover the quarter mile in 15.3 seconds – fast enough to hang with the more sporting muscle cars of the day. Here's How Popular The '90s Impala SS Was Via: Bring a Trailer For 1994, GM shifted just 6,300 Impala SSs, but the following year, when Dark Gray Green and Dark Cherry Metallic were added to the color options, the company managed to sell more than 21,000, according to Hagerty. Things got even better in 1996, with another 42,000 sales. Unfortunately, for the growing legions of the Impala SS, the car was killed off in 1996 due to the B-body line being discontinued. Since then, the '90s Impala SS has become a cult muscle car star. The model is especially revered in hip-hop circles, embodying a low-key inner-city counterculture. There is nothing more menacing than an all-black Corvette-engined sedan. One celebrity fan is Atlanta-based rapper Killer Mike, the political activist and one-half of the hip-hop duo Run the Jewels. Buying An Impala SS In 2025 via Bring A Trailer Despite the Impala SS settling into classic muscle car status, and coming from a time when brutish V8-powered sedans were few and far between, it is somewhat surprising how affordable these cars are. A 1994 Chevrolet Impala SS will cost on average $18,300 in good condition, says Hagerty's Valuation Tools, with prices remaining the same for the following two years. For comparison, a 1961 Chevrolet Impala SS with a 305-horsepower 348-ci will set you back $71,300 in 2025.Sources: Hagerty.com