The Benefits of a Custom Rear Diffuser
Aggressive Rear-End Styling
A well-designed rear diffuser instantly elevates your vehicle's presence. It fills the gap under your rear bumper with purpose-built styling that suggests performance, even when parked. Combined with performance exhaust and quality exhaust tips, your rear-end transforms into a cohesive, track-inspired statement.
Improved Aerodynamics
Our aftermarket rear diffusers aren't just for show. They manage airflow exiting from under your car, reducing turbulence and potentially generating downforce at speed. While street driving won't show dramatic effects, you can appreciate the added stability. Pair your diffuser with canards up front for balanced aerodynamic improvements.
OEM-Fit Quality
Every custom rear diffuser in our range is built to fit like factory equipment. That means proper mounting points, accurate dimensions, and a finish that integrates seamlessly with your existing bodywork.
Easy Installation
Most rear diffusers are installed using existing mounting locations or simple hardware included in the kit. Professional fitting is available if you'd prefer expert hands on the job.
Why Choose Nine Motorsport for Your Aftermarket Rear Diffuser?
Genuine Products
We stock carbon fibre rear diffusers and other materials from manufacturers we trust. We sell what we'd fit to our own cars because we're enthusiasts first, retailers second.
Expert Advice
Wondering if a diffuser will work with your exhaust setup? Curious about finishes? Our team provides honest guidance based on hands-on experience. We'll help you choose a rear diffuser that complements your build and meets your goals, complete with car tuning services to maximise your setup's potential.
Australia-Wide Shipping
See diffusers in person at our Springvale workshop, or order online for delivery anywhere in Australia. Most items ship fast from our in-stock inventory or can be pre-ordered. Plus, we keep you updated every step of the way.
12-Month Guarantee
Professional installation through Nine Motorsport comes with our comprehensive 12-month guarantee. We stand behind our workmanship because quality matters.
Ready to Complete Your Rear-End Build?
Browse our range of aftermarket rear diffusers online or visit our Melbourne showroom to see finishes and fitment up close. Whether you're chasing a custom rear diffuser or adding the final touch to a comprehensive build, we'll help you find the perfect match.
Got questions about compatibility or installation? Reach out today.
Rear Diffuser FAQs
Do I need to modify my exhaust to fit an aftermarket rear diffuser?
Not usually. Most rear diffusers are designed to accommodate factory or aftermarket exhaust configurations. However, some aggressive setups may require minor trimming or specific exhaust tip positioning and it can be from a case by case basis.
What's the difference between single-fin and multi-fin diffuser designs?
Multi-fin diffusers typically offer more aggressive styling and potentially better aerodynamic performance by channelling airflow through multiple passages. Single-fin or minimal designs provide a cleaner, subtler look while still managing underbody air. Your choice comes down to aesthetic preference and intended use.














































