Rear roof spoilers — especially those mounted directly above the rear window glass — are more than aesthetic upgrades. They’re functional aerodynamic tools that help reduce rear glare, enhance airflow, and minimize UV exposure — crucial considerations for vehicles in Australia's climate. When selecting a visor-style spoiler, choosing the right material significantly impacts fitment, durability, and long-term performance.
Material Comparison for Rear Window Roof Spoilers
| Material | Best Use Case | Key Features | Cost Range |
|---|---|---|---|
| ABS Plastic | OEM-style roof spoilers mounted above rear glass | Lightweight, durable, simple to install | 💰 Lower |
| Acrylic (Perspex) | Tinted visor-style spoilers with sleek finish | UV-stable, smoked clarity, aerodynamic appearance | 💰💰 Mid |
| Fibreglass (Hand Laid FRP) | Custom painted spoilers for stylised builds | Superior strength-to-weight ratio; often lighter than reinforced ABS; zero heat-warp | 💰💰 Mid-High |
ABS Plastic: OEM-Grade Function
ABS plastic is widely used in factory-style spoiler applications. It hugs the rear glass curvature with a balanced blend of strength and simplicity. Most ABS spoilers install using automotive-grade tape or OEM mounting points.
- Pros: Tough under impact, budget-friendly, easy DIY install
- Cons: Limited paintability, can dull with prolonged UV exposure, is a thermoplastic
Acrylic (Perspex): Premium Style & UV Performance
Perspex is the go-to material for smoked-tint spoilers. It offers excellent visual clarity and withstands high UV levels — ideal for warm climates and vehicles with side window shields.
- Pros: UV-resistant, sleek finish, trim-compatible
- Cons: Requires careful install to unlock full durability, precise mounting required
Fibreglass (Hand Laid FRP): Performance & Customisation
Hand Laid FRP is the professional choice for custom builds. Unlike mass-produced plastics, FRP is a thermoset composite. This means once it is cured in the mould, it becomes chemically stable and will not warp, sag, or soften under the intense Australian sun - a common issue with cheaper thin-wall plastics.
- Pros: Significantly more rigid than ABS; can be thinner and lighter while maintaining strength; 100% heat tolerant; easier to repair if damaged.
- Cons: Requires professional prep/paint; more labour-intensive to manufacture.
FAQs: Choosing a Rear Roof Spoiler Material
Do rear spoilers sit directly above the rear glass?
Yes – roof spoilers sit flush above the rear window to enhance airflow and styling without altering boot or hatch structure.
Can I paint ABS spoilers?
Yes – ABS can be painted with proper prep. Light sanding, plastic primer, and flexible paint yield the best results.
Will Perspex crack in heat?
Perspex is UV-resistant and heat-tolerant, making it ideal for Australian conditions. Cracking only occurs with poor installation or excessive stress.
Is fibreglass always heavier than plastic?
No. In fact, automotive-grade Hand Laid FRP is typically lighter than an equivalent ABS spoiler. Because FRP is naturally much stiffer, we don't need to make the walls as thick to prevent highway vibration. This allows for a lightweight, high-strength part that puts less stress on your rear window seals.
Why does Hand Laid FRP cost more than ABS?
FRP is a handcrafted product. While ABS is machine-injected in seconds, each FRP spoiler is hand-layered at a workshop to ensure consistent thickness and structural integrity. You are paying for a superior material that offers better long-term durability and a custom-painted finish.
Which rear roof spoiler material lasts the longest?
Perspex offers the best long-term clarity and UV resilience for parked vehicles and hot climates. ABS suits daily use, while fibreglass excels in custom applications.
🛠️ Choosing the Right Material: Not all body parts are created equal. While many accessories use mass-market plastics, Hand-Laid FRP components are engineered specifically for high-heat Australian environments.
Before you commit to your next build, understand the technical differences between FRP, Polypropylene (PP), and Carbon Fibre in this expert guide from our manufacturing partners: FRP vs Plastic Body Kits: The Honest Australian Guide to Materials.
| Buyer Need | Best Material | Why |
|---|---|---|
| UV-tinted clarity + visual edge | Acrylic (Perspex) | Stylish, UV-resilient, pairs with trims |
| Factory-style durability | ABS Plastic | Affordable, strong, quick install |
| Custom painted look | Fibreglass | Paintable, stylisable, high rigidity |
Explore Related Products & Resources
- Holden Commodore VT–VZ Rear Roof Spoiler – HIC Premium
- Subaru Impreza Accessories – Weather Shields and Roof Spoilers
- Roof Spoiler Installation Guide
- Spoiler Quality & Fitment Overview
Explore more premium HIC upgrades built for Australian conditions at HIC Australia