13 Coolest Custom Cars Built by Ringbrothers

Custom cars are more than just vehicles — they’re a statement. Over the past decade, the custom car market has grown significantly, with a global value estimated at over $14 billion in 2023. What’s driving this boom? Drivers want more than off-the-lot designs — they want power, personality, and precision.

In the small town of Spring Green, Wisconsin, two brothers are rewriting the rules of what custom cars can be. Jim and Mike Ring, the masterminds behind Ringbrothers, have been shaping car bodies and honing their skills since childhood. Despite running a collision repair shop as their primary business, the brothers have also dedicated themselves to crafting jaw-dropping, high-performance builds. These cars don’t just look good–they’re engineering marvels.

Espionage

Many ’60s and ‘70s cars would fail modern safety test, but not the Espionage. Espionage takes the classic 1965 Mustang to new heights. However, with a 959-horsepower 427ci Wegner Motorsports-built V8 and a 2.9-liter Whipple supercharger, this car is all about raw power.

The drivetrain includes a carbon fiber driveshaft and a DSE Ford 9-inch rear end that is built to handle the muscle. And those bold carbon fiber panels? They widen the Mustang by two inches on each side, all painted in a striking “Spy Green.” Though named Espionage, this car is anything but subtle — its presence is undeniable.

Blizzard

Built in 2013, Blizzard was crafted from a 1965 Mustang. According to Mike Ring, Blizzard features the first-ever fiber doors crafted in their shop. To add a touch of tradition, the Ringbrothers incorporated an aluminum G.T. 350 R-style front fascia that blends the old and the new.

Blizzard’s power comes from a Wegner Motorsports NASCAR Sprint Cup Motor 351-based 427 cid V8 engine, while the power generated is sent to the wheels through a Bowler 5-speed transmission. As for the wheels, the brothers slammed on a set of HRE 560R Series, while the tires are Nitto INVO. Now, what’s a cool custom job without a sleek finish? Blizzard is finished off with a BASF Glasurit Waterborne white paint.

Reactor

The Reactor is daring with its details, and there’s plenty to marvel at about the build. According to the Ringbrothers, the Reactor boasts an astounding 70 unique custom components, which include a Roush 427 IR engine with an output of 551 hp and 525 lb-ft of torque.

From the front spoiler vents to the hood bezel and gas cap, every component on the Reactor highlights the Ringbrothers’ dedication to perfection. Carbon fiber plays a huge role — the front and rear end bumpers, rear taillight panels, and front lower valance are all crafted from this solid material, ensuring the Reactor could never make the list of muscle cars with the worst design flaws.

Defector

The Defector is powered by a 6.4-liter Hemi V8 tuned by Wegner Motorsports. The engine uses a Holley Dominator fuel management system. As the Ringbrothers’ first Mopar-based build, the Defector is a labor of love. According to the Ringbrothers, it took 4,700 hours of meticulous craftsmanship to bring this vision to life.

Another part of the build includes a Bowler Chevy 4L80E 6-speed transmission with a QA1 carbon fiber drive shaft to send all that power to the wheels. The brakes are Baer 6-piston fitted on the front and rear, while the exhaust is Flowmaster 44 stainless steel with custom headers from Ringbrothers. The Defector is covered up with a custom BASF Glasurit Waterborne paint called Greener on the Other Side.

Valkyrja

Under the Valkyrja’s hood is a 416 cubic inch LS3 engine, boosted by a 2.9L supercharger, delivering a staggering 890 horsepower to the rear wheels through a reworked Bowler six-speed Tremec transmission. A Flowmaster stainless steel super 44 exhaust amplifies the beastly sound, while its robust suspension and reinforced rear end ensure it handles all that power with ease.

Wrapped around its custom HRE wheels are Michelin Pilot Sport 4S tires on all four wheels. The BASF Glasurit green custom paint finish on the Valkyrja has turned the 1969 Camaro into an alluring engineering masterpiece.

Defiant!

In the Defiant, Ringbrothers take the classic Javelin AMX and transform it into an absolute powerhouse. Under the hood lies a Wegner Motorsports 6.2-liter Hemi Hellcat Mopar Crate V8 engine, boosted by a massive 4.5-liter supercharger, which helps it unleash a jaw-dropping output of 1,036 hp.

With six-piston brakes and a four-speed automatic transmission, this beast combines raw power with precision control. Majestically finished with a custom base coat paint called the Jalop Gold, the Defiant is also fitted with HRE S2 series wheels and Michelin tires.

Ballistic

Ballistic is a one-of-a-kind Mustang courtesy of the Ringbrothers, and it was unveiled at the 2016 SEMA Show. The first widebody convertible ever built by the brothers, Ballistic brings the heat with a Shelby GT500-sourced 5.8-liter V8 tuned for maximum performance.

Its roar is amplified by Flowmaster mufflers and a custom stainless-steel exhaust, ensuring it’s heard before it’s seen. The build also includes RideTech shocks and a DSE hydro-formed front subframe with 4-link rear suspension and front sway bars. Ballistic is brought to a halt using 15″ Baer Mono Block brakes on the front wheels and 14″ on the rear.

SPLITR

SPLITR is powered by a naturally aspirated 7.0-liter Ford Racing engine, fine-tuned by Wegner Motorsports and paired with a T56 Tremec 6-speed manual transmission. While the exact horsepower is a mystery, we can safely put it around the 500+ range.

To enhance its handling, Detroit Speed crafted a custom Mustang Aluma-Frame front suspension to make SPLITR as agile as it is powerful. With an exquisitely applied Ford Racing Red paint from BASF Glasurit 90 Line, the SPLITR is really unmistakable even from afar. For this build, the brothers also adopted Nitto INVO ZR tires on HRE C1 Series C103 wheels.

Producer

Built in 2011, the Producer is a nod to old-school muscle with a modern twist, as it is originally a 1965 Mustang. Powered by a Keith Craft 427 stroker, this beauty delivers 740 hp — all built the traditional way to honor the Mustang’s roots. But Jim and Mike Ring didn’t stop there.

They designed the custom three-piece wheels and replaced every part of the car except the grille. A Bowler Performance T56 transmission sends all the power to the rear wheels, the suspension comes from Art Morrison and uses AFCO coilovers.

Razor

Razor is all about sharp design and power. Beneath its carbon fiber hood, there’s a Ram Jet ZL1 engine, delivering a solid 510 hp and 493 lb-ft of torque. Paired with a Tremec six-speed transmission, the Razor is surely built for an action-packed drive.

Its sleek two-tone paint scheme adds a bold finish and commands attention wherever it goes. On the inside, the Razor receives a Momo steering wheel alongside Audi TT bucket seats to make any gearhead feel right at home in the driver’s seat. Furthermore, the brothers also fitted the build with an Alpine stereo, which includes Blue Tooth and navigation.

Switchback

Switchback proves that Ringbrothers can do more than just classic muscle — it’s a bold reimagining of the 2013 Mustang. Powered by a ProCharger supercharged 5.0-liter V8, this car cranks out an impressive 575 hp, amplified by a Flowmaster 409S dual exhaust.

Its striking look matches its performance. The Switchback features a carbon-fiber body kit, aluminum side vents, and a modular carbon-fiber hood with a customizable insert. Notably, the Switchback sits on staggered 19- and 20-inch wheels wrapped in Nitto tires, ready to give you a treat.

ADRNLN

While we remember the ’70s for several iconic events, it was also the era in which the De Tomaso Pantera was launched. Originally meant to be a 1971 Pantera restoration, ADRNLN is born from a story of passion and legacy, and it became a tribute after its owner’s passing, completed with one request: keep the bold yellow paint.

Under the hood, a Wegner Motorsports LS3 V8 delivers 600 horsepower, but it’s the details that steal the show. With Nike-designed features like waffle-pattern pedals and custom dash materials, plus a matching pair of golf shoes, ADRNLN fetched a whopping $330,000 at auction.

Dragon

The Dragon is simply a beast on four wheels powered by a potent Roush 427 IR crate engine which churns out 550 horses. Originally, the Dragon is a 1970 Mustang, and Ringbrothers concluded its transformation in 2010. The Dragon’s body is a work of art, crafted from carbon fiber and a machined billet for a lightweight yet aggressive look.

To ensure great stopping power, Ringbrothers equipped it with massive Baer Pro plus brakes, complete with a brake line for ultimate control. The original unibody design was swapped out for a custom frame with a belly pan for an unshakable foundation.