Your Mustang, RTR's hands: Signature Package opens the door to a one-of-a-kind build

RTR Vehicles launches a personal customization program for Spec 2 and Spec 3 owners — built at the RTR Lab in North Carolina, with up to 870 hp on the table.

RTR Vehicles is stepping into territory where ordinary tuning ends. The company has launched the Mustang RTR Signature Package — a program for owners of the 2024-and-newer Mustang RTR Spec 2 and Spec 3 who want more than a catalog parts kit and would rather build the car alongside the RTR team itself.

The idea is a personal approach. The customer works directly with RTR specialists, discussing the exterior, finishes, graphics, badge colors, painted aero components and possible technical upgrades. The build is carried out at RTR’s headquarters — the so-called RTR Lab in Concord, North Carolina. It feels closer to a coachbuilding atelier than to a classic catalog where you tick boxes for wheels, decals and suspension parts.

For the Mustang world, this is a meaningful move. Shelby has traditionally sold power, name and a finished image, but RTR is putting the focus on the owner’s involvement in the project. That makes sense for Spec 2 and Spec 3 buyers in particular: these cars aren’t bought as another Mustang GT, but as machines with a more aggressive identity tied to drifting, street culture and the personal style of Vaughn Gittin Jr.

The Signature Package does not replace the RTR trims themselves. Spec 2 remains the more street-focused option with visual and chassis upgrades, while Spec 3 is already a serious step toward a supercharged V8. The current RTR lineup also includes more extreme versions: the 2026 Spec 3 is rated at 810 hp and 615 lb-ft, while the wide-body Spec 5 pushes output up to 870 hp and 660 lb-ft.

What matters is that the Signature Package isn’t just cosmetics. Within the program, owners can get a full powertrain upgrade: a Whipple Stage 2 supercharger raises output to those same 870 hp, with RTR Tactical Performance coilovers and an RTR by Borla exhaust thrown into the mix. In other words, a car that comes out of the program can match the top Spec 5 on power while remaining visually unique.

The package itself costs around 12,500 dollars. That sits on top of the cost of an already-purchased Mustang RTR Spec 2 or Spec 3: the base 2026 Mustang RTR Spec 2 upgrade package starts at 18,995 dollars before the Mustang GT itself. Compared to budget-bending bespoke programs like Porsche Exclusive Manufaktur or Q by Aston Martin, 12,500 dollars for one-on-one work with an RTR designer looks almost modest.

Set against the factory Mustang RTR EcoBoost — which Ford and RTR built as a more accessible driver’s version with parts borrowed from the Dark Horse — the new Signature Package is the other pole. There you get a factory-built package for a broad audience; here you get an individual story for someone who already owns an RTR and wants to take it further.

For the buyer the upside is clear: the car becomes more than just «another RTR», it becomes a project with a personal signature, and it does so without demanding the kind of money that a Mustang GTD asks for. In the Mustang world, rarity and a build story often matter as much as horsepower.