This 1,700-Mile 2023 BAC Mono R Is a Street-Legal Formula Car Chasing Six-Figure Bids

A 2023 BAC Mono R with just 1,700 miles on its carbon-fiber tub is currently up for grabs on Bring a Trailer, where bidding has already blown past $210,000 with several days still left on the clock. Built as a single-seat, road-legal distillation of open-wheel racing, this Mono R is one of the purest expressions of Briggs Automotive Company's less-is-more philosophy, and it's easy to see why collectors are circling.

Power comes from a 2.5-liter inline-four built by Mountune Racing, sent through a Hewland FTR six-speed sequential gearbox and a Powerflow limited-slip differential — a drivetrain layout borrowed more from formula racing than anything found in a typical road car. The chassis is a TIG-welded steel spaceframe wrapped in carbon-fiber composite bodywork, finished here in a translucent burgundy over an asymmetrical gold livery that shows off the weave beneath the paint. Underneath, 17-inch carbon-hybrid wheels wrap around carbon-ceramic rotors squeezed by AP Racing calipers, while adjustable Öhlins dampers, a centrally mounted headlight pod, and an F3-style intake snorkel keep the aesthetic firmly in single-seater territory.

Since there's only room for one, the cockpit is trimmed in black leather and microsuede, with a multifunction steering wheel, a quick-release hub, a Sabelt harness, and a cockpit cutoff switch that wouldn't look out of place on a paddock grid. This particular car last changed hands after an April 2025 sale on Bring a Trailer, and its current dealer-consignor is offering it again with a Bell/BAC Design helmet, a clean Carfax report, and a California title, plus only 1,700 miles logged since new.

Cars like the Mono R sit in a strange spot in the collector market: too new and too low-volume for Hagerty's valuation tools to have built out a price guide entry yet, which is itself telling. Hagerty's data does track how ultra-limited, track-focused machines hold their value once they leave new-car pricing behind, and the pattern tends to repeat: values hinge on mileage, originality, and how badly the next owner wants bragging rights rather than on horsepower alone. We've used those same Hagerty tools to frame the market around other scarce, single-purpose cars, including a no-reserve 1984 Ferrari 308 GTS Quattrovalvole and a one-of-200 2022 Shelby Super Snake Coupe, and the same logic applies here — scarcity plus provenance, not raw numbers, is what moves the needle.

If a single-seat formula car isn't quite exotic enough, the current crop of Bring a Trailer listings has no shortage of company. We've also covered a supercharged Acura NSX-T that hit BaT with a salvage title in tow, and a well-traveled SCCA Trans Am/GT1 Camaro that raced across three countries before landing on the market — both proof that the line between race car and road car keeps getting blurrier. Whether this Mono R sells for six figures or seven, it's a reminder that some of the most interesting collector-car stories right now aren't about classics at all, but about how quickly the ultra-limited cars of today become the sought-after oddities of tomorrow.