Midtown’s most remarkable landmark-tower rebirth is racing to the finish line.

Luxury sports car manufacturer McLaren automotive is close to leasing 550 Madison Ave.’s remaining retail space for a spectacular showroom, multiple sources told The Post.

A dome of silence shrouds the advanced negotiations, with brokers and reps either declining to comment or failing to respond to calls and emails.

But if the deal with landlord Olayan America is struck, it would complete the “Chippendale”-top  tower’s stunning comeback story. The 750,000-square-foot landmark’s office space is nearly 100% filled with premier tenants including Chubb, Aquarian Group, private equity firm Clayton Dubilier & Rice, and Hermes. Rents are above $200 per square foot for some floors.

The only empty space is on the ground floor retail corner at the south end, which has a temporary Museum of the City of New York exhibition.

The 15,000-square-foot, north-end retail space is home to Simon Kim’s just-opened, three-level hospitality complex including Korean steakhouse Cote, Bar Chimera and a soon-to-come omakase eatery from three Michelin-star chef Masahiro Yoshitake.

Olayan bought the pink granite property, former home of AT&T and later of Sony, for $1.4 billion in 2016 and launched a $300 million partial redesign under the watchful eye of the Landmarks Preservation Commission. Previous owners had abandoned a hotel and residential conversion plan, leaving Olayan with a vacant, 42-story tower in the heart of Manhattan’s most prestigious  district.

Olayan comprehensively re-tooled the lobby and office floors for 21st-century use and enlarged the retail-level windows. It also widened the little-used pedestrian arcade between East 55th and East 56th streets and re-invented it as a lavishly landscaped oasis with three food kiosks under a new, 70-foot-high glass canopy.

McLaren Automotive is the road-car subsidiary of McLaren Group, a venerable British racing organization with a legacy of Formula 1 and Grand Prix triumphs in Europe. It was founded by champion driver Bruce McLaren – who led the McLaren racing team, a predecessor to McLaren Group – before he died at age 32 in a  driving accident.

McLaren would be the latest marquee-name automaker to launch a Midtown showroom, following Aston Martin and Ferrari.