What makes R4™ different from traditional sunroof window tint?

The difference comes down to both the material and where it is installed.

Most automotive window films are built around a PET — polyethylene terephthalate — base and are installed on the interior surface of the glass. PET is thin, dimensionally stable, and highly effective for conventional window tint applications. However, higher-performance films can also increase the amount of solar energy absorbed within the glass system. On large panoramic roofs and sunroofs, that additional heat absorption can contribute to greater temperature differences across the glass, increasing thermal stress.

Instead of using a traditional PET construction on the interior of the glass, R4™ is built around a flexible TPU — thermoplastic polyurethane — base and applied to the exterior surface of the sunroof. Its heat-rejection technology is positioned before solar energy passes through the glass, helping reduce the amount of heat that must be absorbed and managed by the glass itself. By managing solar energy from the exterior, R4™ is designed to provide strong heat rejection while minimizing additional thermal loading on large glass panels. This makes it especially well suited for panoramic roofs, where heat buildup and uneven temperature distribution can become a greater concern.

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The TPU construction also provides flexibility, impact resistance, and durability that traditional PET window tint is not designed to provide, giving R4™ the ability to protect the glass itself in addition to improving cabin comfort.

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Exterior heat rejection. Flexible TPU protection. Less thermal stress on the glass.

Built specifically for the demands of modern panoramic roofs.

Cashew Vs. 3H

Many traditional PET windshield protection films use a relatively hard surface coating—often around 3H pencil hardness. That can work well for collector cars, weekend vehicles, and applications where windshield wiper use is limited. But daily-driven vehicles, track cars, and cars regularly exposed to mountain roads, debris, weather, and constant wiper use demand something more forgiving.
 

That’s where the Cashew® top coat comes in.

Cashew Co., Ltd. is a Japanese coatings and synthetic-resin manufacturer whose roots date back to coatings developed from plant-based phenolic compounds extracted from cashew nut shells. The company has since developed advanced functional and UV-curable coating technologies used across automotive, electronics, and other demanding applications, including coatings engineered for transparency, wear resistance, and scratch resistance.

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R4™ uses a self-healing resin top coat designed differently from a conventional rigid hard coat. Rather than simply relying on surface hardness, the coating is engineered to recover from light scratches, windshield-wiper marks, and everyday surface wear. Minor imperfections can gradually heal at ambient temperatures, while gentle heat can accelerate the recovery process.

The result is a surface better suited to the environment R4 was actually designed for: daily drivers, enthusiast cars, track use, and vehicles that see real road miles.