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Roush-tuned Factory Five Mk4 Roadster with 427R V8 heads to auction
A 2019 Factory Five Racing Mk4 Roadster fitted with a Roush Performance 427R V8 and a five-speed manual is being offered with 4,900 miles and a recent round of driveline and exhaust work.
By Eleanor Ellington · 4 min read
A 2019 Factory Five Racing Mk4 Roadster powered by a Roush Performance 427R V8 is being offered for sale by its current owner, who bought the car directly from its builder in 2019. The roadster has covered 4,900 miles and comes with a clean Michigan title in the seller's name, which describes the vehicle as a 2019 Assembled Convertible. The listing presents the car as a complete, lightly used example of the kit-built roadster, with the seller's own work and documentation forming the basis of the offer.
The heart of the car is the Roush 427R V8, fitted with a Holley four-barrel carburetor, an Edelbrock Victor Jr intake manifold, a PowerMaster alternator and MSD ignition components. Power reaches the rear wheels through a Tremec TKO five-speed manual gearbox and an 8.8-inch rear axle with a limited-slip differential. According to the seller, the clutch assembly, flywheel and spark plug wires were replaced in 2025, and the side-exit exhaust system was installed the same year. The seller's account of the 2025 work places the most recent mechanical attention on the drivetrain and the exhaust, rather than on the chassis or the bodywork.
Visually, the Mk4 wears a silver fiberglass body with gray over-the-top stripes. Its equipment list includes a hood scoop, wind wings, windshield-mounted mirrors, a bright roll hoop, a LeMans-style fuel filler cap and quick jack bumperettes. The seller reports paint protection film and an exterior ceramic coating, which are intended to preserve the finish, along with LED ambient lighting under the hood and in the trunk. These additions are described as aftermarket upgrades layered onto the factory-built shell rather than as changes to the roadster's original form.
Underneath, the roadster rides on adjustable coilover dampers and selectable electric power steering. Wilwood disc brakes are fitted, with six-piston calipers at the front and four-piston units at the rear. The Halibrand-style wheels are shod with Michelin tires at the front and Toyo tires at the rear, a combination that suits the car's performance-oriented setup. The suspension and braking hardware are the kind of components buyers of kit-built roadsters typically select when they want track-capable handling from a street-legal car.
Inside, the cockpit is trimmed in black upholstery with heated low-back bucket seats, two USB-A outlets, footwell LED lighting, latch-and-link Simpson harnesses and a powder-coated transmission tunnel. A wood-rimmed steering wheel sits in front of a Speedhut GPS speedometer and tachometer, which were installed in preparation for the sale. The digital odometer reads 4,900 miles. The seller's decision to fit the instruments ahead of listing signals an intent to present the interior as ready to drive rather than as a project in progress.
The sale includes spare parts such as the removed sidepipes, an interior carpeting kit, a rear-view mirror and Simpson harness accessories. Including the replaced exhaust components alongside the car means a buyer receives the original hardware along with the installed system. Additional underside photographs are provided in the listing gallery, giving prospective buyers a look at the chassis and drivetrain beyond the cosmetic finish.
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