It's not often that a car sits unsold for years, but it does happen occasionally. That's the case with this 2001 Mercedes-Benz SL600 spotted by Motor1. The V-12 convertible was never titled, and is now being offered for sale by Mercedes through the automaker's Classic Center in Irvine, California.

This is one of the final R129-generation SL models built by Mercedes; the successor R230 SL went into in production in 2001. The R129 had a long run, starting production in 1989. The 6.0-liter V-12 engine was added in 1992 for the 600SL model. The name was changed to SL600 in 1993, and the engine was given a modified fuel-injection system to reduce emissions.

The updated V-12 produces 394 horsepower, allowing for a 0-62 mph run of 6.1 seconds, according to Mercedes. Top speed is electronically limited to 155 mph.

Because this car was built after 1995, it has a 5-speed automatic transmission. The gearbox was fairly advanced for the period, sporting its own electronic control unit that could adapt shift behavior to different driving conditions and communicate with the engine management system.

This car has the optional AMG Styling Package, which includes a different front spoiler and side skirts, as well as AMG wheels. The car has just 427 miles on its odometer.

The price of originality is $135,000. That's about $10,000 more than it cost in 2001 and $20,000 more than a 2020 SL550, the current range-topping SL. But buyers seem willing to pay big bucks for time-capsule collectibles. In 2017, a 1996 SL500 with just 80 miles on the odometer sold for $73,000, a tidy sum for this lower-level R129 model.