Think a BMW M5 makes a great sleeper? Munich’s super-sedan is about as discrete as a dayglo pink McLaren compared to this scruffy Hemi-powered Plymouth Satellite that’s currently for sale on Bring-a-Trailer.

Unlike their late 1960s counterparts with their wild color schemes, eye-catching, air-catching hood scoops, sports wheels and prominent graphics, the first wave of muscle cars that decade mostly hid their massive powerplants in plain wrappers.

Having made its new 426 cu-in (7.0-liter) Hemi available to racers in 1965, Chrysler expanded availability to regular street cars for 1966. Dodge buyers could get it in the sexy new Charger coupe, but Plymouth didn’t have an equivalent, so its customers had to take the monster Hemi motor in a Belvedere, or its upscale Satellite spinoff.

Base Satellites got a meek 180 hp (183 PS) 273 cu-in (4.5-liter) V8, while the Hemi was officially rated at 425 hp (431 PS), and actually put out far more, making it almost three times as powerful. In an April 1966 test Car & Driver recorded 5.3 seconds to 60 mph (97 km/h) and ran the quarter-mile in 13.8 seconds in a four-speed Hemi coupe. Yet from the outside, with its simple hubcaps and flat hood, there were very few cues to the extra performance.

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And there are even fewer cues on the tired 56-year-old car you see here. Drive this down the freeway and the average SUV pilot in the next lane would never guess that it could have smoked a Ferrari in its heyday, and is still capable of giving plenty of modern cars a fright.

Unfortunately, before the next owner can drive this one it’s going to need some fettling, and we’re not talking about rust repairs. The Hemi and its four-speed manual transmission (a combo ordered by only 503 people in 1966) are still in place, but the motor isn’t currently running and the seller doesn’t know when it was last run. But anything is fixable with time and money. It’s just a matter of how much you want to throw at it.

This car needs, deserves and, thanks to its rarity, will likely get a heap of money thrown at it to bring it back to top condition. But it’s fun to imagine what it would be like if you overhauled the drivetrain and brakes, left the body, and spent your weekends embarrassing BMW drivers. Whichever scenario you prefer, you need to get your bids in before the auction ends on June 13 to be in with a chance of owning it.

But if you miss out, or you like the Detroit ninja theme but prefer a turnkey car, there’s a Dodge equivalent, a 1966 Coronet Hemi in perfect condition, closing the following day on the same auction site.