Estimated high price: Up to $1,480,000
Technically, the world "gullwing" applies to any door that hinges on the roof, but for many, it's synonymous with the Mercedes 300SL. James May once referred to this car as the genesis of all supercars, and with good reason: it's more or less the road-going variant of Mercedes' 300SL race car, which enjoyed one of the most dominant runs in motorsport history in the mid-'50s.
As a 240hp road car, it could hit 165mph, back when cars like Corvettes could barely touch 120. Combine that with timeless looks, and you see why it's a seven-figure car.