A custom body kit changes the exterior appearance of a vehicle — adding, replacing, or modifying panels, bumpers, skirts, spoilers, and other body components. Done well, a body kit transforms how a car looks and can meaningfully affect aerodynamic performance. Done poorly, it looks like an afterthought and fits like one too. The difference usually comes down to how the kit was designed and what process was used to make it. Here’s what goes into a custom body kit and what to look for when you’re planning one.
What Is a Custom Body Kit?
A custom body kit is a set of exterior components — typically front and rear bumpers, side skirts, fender flares, splitters, diffusers, and spoilers — designed to modify the appearance or aerodynamics of a specific vehicle. Off-the-shelf kits exist for popular platforms, but a truly custom kit is designed for a specific car, a specific look, and specific performance or fitment requirements that generic kits can’t meet.
Custom kits are specified when the vehicle is rare or modified enough that no catalog kit exists, when the design vision is unique, or when fit quality matters enough that a purpose-built solution is worth the investment. For heavily modified vehicles, custom work is often the only option. For more on how 3D scanning enables precision automotive fabrication, see our guide to scanning classic and custom cars for aftermarket fitment.
What Materials Are Custom Body Kits Made From?
Material selection affects weight, flexibility, durability, and cost. The main options used in professional body kit fabrication:
Fiberglass (GRP) is the traditional choice — lightweight, relatively inexpensive, paintable, and easy to repair. Fiberglass body panels can be produced in small quantities from molds at reasonable cost. More brittle than OEM plastics; low-speed impacts that would flex a factory bumper may crack fiberglass.
Polyurethane (PU) is flexible and impact-resistant, closer to OEM bumper material in behavior. More expensive to produce than fiberglass but significantly more durable in day-to-day use. Better suited for street-driven vehicles that will see regular minor impacts.
Carbon fiber is lightweight and visually distinctive. Used for performance-oriented applications where weight reduction matters — splitters, diffusers, hoods, wings. Higher cost than fiberglass or polyurethane; repair is more complex.
ABS plastic is injection molded and practical for production runs. Less common in one-off custom work due to tooling costs, but cost-effective at quantity.
The right material for a given kit depends on how the car will be used, the budget, and whether appearance or durability is the priority. A track car optimized for weight savings has different requirements than a street car that needs to survive parking lot contact. Our molding and casting services cover fiberglass and polyurethane panel production for custom automotive work.
How Does 3D Scanning Improve Body Kit Fitment?
Fitment is where most custom body kits succeed or fail. A panel that was designed from photos or generic measurements will rarely fit cleanly — there will be gaps, misaligned edges, and mounting points that don’t line up. Fixing fitment problems after fabrication is expensive and sometimes impossible without starting over.
3D scanning the vehicle before design begins eliminates this problem. The scan captures the exact geometry of the existing body — every curve, every shut line, every mounting surface — and provides the design team with accurate reference data. New panels are designed to interface with that real geometry, not an approximation of it.
This is the approach we use for custom automotive work at Kemperle. Scanning first means the design is grounded in reality from the start, and fitment problems are caught in the CAD model rather than on the car. Our aftermarket automotive work covers everything from individual custom panels to full body kit development.
What Does the Design and Fabrication Process Look Like?
A professional custom body kit development process typically runs through these stages:
Vehicle scan. Capture the existing body geometry as a reference baseline. The scan includes the surfaces the new panels will interface with — adjacent body panels, mounting locations, and any structural features the kit needs to clear or attach to.
Design in CAD. Develop the new panel shapes in reference to the scan data, ensuring all interfaces and mounting points are correct before any physical work begins. This is where the aesthetic and functional intent of the kit is worked out in detail.
Prototype. 3D print or CNC cut prototype panels to verify fit on the actual vehicle before committing to production tooling. This step is where fitment issues surface at the lowest possible cost — a printed mockup is cheap to modify; a finished mold is not. See how this connects to reverse engineering vehicle panels for complex geometry.
Mold making. Produce molds from the approved prototype geometry for fiberglass or polyurethane casting. Mold quality determines the quality of every part pulled from it — this is not a step to cut costs on.
Production and finishing. Cast final panels, trim, drill, and prep for paint. Surface preparation before paint is critical for fiberglass and polyurethane — the material won’t hide preparation shortcuts the way metal bodywork can be worked and re-worked.
Skipping the prototype step to save time almost always costs more in the end — fitment corrections at the mold stage are expensive. A 3D printed mockup that confirms fit before tooling is one of the highest-value steps in the process.
Working with Kemperle on Custom Body Kit Projects
We handle the full workflow in-house: scanning, CAD design, prototyping, and fabrication. For clients who come to us with an idea and a vehicle, we take the project from the first scan to panels ready for paint. For clients who already have CAD data or a design direction, we can step in at any stage.
Our scanning capability means we’re not working from approximations — the geometry we design against is the actual car, not a generic model or a set of hand measurements. That makes a real difference in how the finished kit fits, particularly on vehicles that have been modified or built up from multiple donor cars where the geometry no longer matches any documented specification.
If you’re planning a custom body kit and want to talk through materials, process, and what the project involves, get in touch or call 718-557-9578. We handle the full workflow from scan to finished panel.
