Leaving a car to sit for years on end can have devastating consequences unless it's sealed in a temperature-controlled lair alongside a team of mechanics hired to keep it in tip-top shape. But that's not possible for every car as some are left by the wayside to rot, like this 1991 BMW 850i, parked in a garden in 2011 and left abandoned. Time hasn't been kind, but that hasn't stopped one mechanic from getting the coupe road-worthy again.

It takes a lot to get the BMW running again, with the latest instalment in the video series showing a lot of work needing to be completed to get it running under its own power. The video starts with the mechanic fixing the clutch pedal, which sticks to the floor when pressed before moving on to the brakes and brake fluid. He then replaces the coolant, fixes the timing chain, and cleans the throttle bodies.

Once he replaces the transmission and differential fluid, the BMW is ready for its first drive in 10 years – and it's a successful one, too. It's not registered, so he wasn't able to drive it on public roads, but the test drive in the shop's car park shows it working properly, capable of moving, steering, and stopping under its own power. However, it's not all roses and sunshine, as the brake pedal is a bit too soft, with the cause likely being the brake pressure accumulator.

The 30-year-old BMW, even for its age, still looks good, even if the Calypso Red paint has seen better days. The interior is also in remarkable condition, with the power tilt-and-telescoping steering wheel still working, along with the memory function. The mighty 5.0-litre V12 lives again, which makes around 300 bhp (223 kilowatts). That's not a lot by today's standards, but it was plenty for the high-end model when it was new.