Since 2011, we’ve serialized our vehicles by generation. Each platform carried a continuous run of serial numbers until that generation came to an end. For example, S197 (05-14 model years) and S550 (18-23 model years) Mustangs shared their own sequence of badge numbers. When the new generation S650 Mustang launched in 2024, the numbering reset to mark the start of the next generation. That structure allowed each generation to stand on its own in RTR history, with every badge representing its place within that era.
Starting with the 2026 model year, we’re introducing a new serialization format across our Mustang RTR Spec vehicles. The first Mustang RTR Spec 2 built in 2026 carries the badge 26-0001. In this new structure, the first two digits represent the model year, while the final four digits represent that vehicle’s production sequence within its specific spec for that year.
Therefore, if you spot a Mustang RTR Spec 2 and see the RTR serial number of 26-0001, that would designate it as the first Spec 2 built for the 2026 model year. Spec 3 and Spec 5 vehicles will follow the same format going forward. Each Spec will have its own serial number sequence tied directly to that year.
“Making the change to annual serial number resets helps us to ensure each customer has the highest possibility of receiving a lower chassis number on their dash plaque, something our customers place high value on,” said Mark Wagner, RTR New Product Development Director. “As our production volumes increase, vehicle counts per generation could have easily reached the thousands. The change also brings us in alignment with Ford and the serialization process of the new Ford Mustang RTR”.
This marks the first time in RTR history that we are offering serial badges with clear yearly designations.
Why make the change now? Because model years matter more than ever. Each year brings refinements, colors, engineering updates, and sometimes major platform shifts. By tying serialization directly to the model year, we are giving every production run a defined identity. Instead of one long generational sequence, each year becomes its own documented chapter in the RTR timeline.
This new format also provides greater clarity for owners and collectors. With a glance at the badge, you will know exactly where your vehicle sits within that specific model year and spec. It strengthens traceability, enhances collectibility, and reinforces the precision that goes into every build.
You’ll also find that the upcoming Ford Mustang RTR EcoBoost will follow the same format, receiving a laser-etched dash plaque before rolling off the Flat Rock assembly line. 
Most importantly, it reflects how we view our vehicles internally. Every Mustang RTR Spec 2, Spec 3, and Spec 5 is not just part of a generation. It is part of a specific moment in time. A 2026 vehicle carries the engineering decisions, design direction, and performance philosophy of that year.
The Ford Mustang has never stopped evolving, and neither have we. From the way we engineer our vehicles to the way we document each build, progress is part of our DNA. Because that small serial badge is more than a number. It’s a marker in our history and in yours.
