Subaru WRX STI VA Performance Style Gloss Black Carbon Rear Bumper Diffuser 2015-2021

Enhance the rear-end styling and aerodynamic performance of your 2015-2021 Subaru WRX or STI with this performance style rear bumper diffuser. Designed specifically for the VA chassis, this upgrade adds a more aggressive lower rear profile while improving airflow management.

This rear diffuser is engineered to integrate seamlessly with the factory rear bumper, creating a more defined and performance-oriented appearance. The multi-fin design helps direct airflow more efficiently under the vehicle, reducing turbulence and enhancing overall aerodynamic stability.

Constructed from reinforced ABS plastic, this diffuser offers a durable and lightweight solution suitable for daily driving and performance builds. Available in glossy black or hydro-dipped carbon finish, it provides flexibility for both subtle OEM+ styling and a carbon-inspired performance look.

Product Specifications

Key Features

• Designed for 2015-2021 Subaru WRX and STI VA models
• Performance style rear diffuser enhances aggressive rear appearance
• Improves airflow management and reduces turbulence
• Multi-fin design for enhanced aerodynamic efficiency
• Constructed from reinforced ABS plastic for durability
• Lightweight design suitable for daily and performance use
• Available in glossy black or hydro-dipped carbon finish
• Precision fitment aligned with factory rear bumper
• Manufactured following ASTM durability standards
• Enhances lower rear bumper definition and styling

Configuration Options

• Gloss Black – Clean OEM-style finish
• Hydro-Dipped Carbon – Carbon fiber appearance finish

Package Includes

• Rear bumper diffuser
• Installation hardware

Note: Professional installation is recommended to ensure proper alignment and secure mounting.

Installation

• Bolt-on installation
• Mounts to factory rear bumper
• No major modifications required
• Installation hardware included
• Professional installation recommended

Fitment

• 2015-2021 Subaru WRX (VA)
• 2015-2021 Subaru WRX STI (VA)

United States: Free shipping available to the lower 48 states across all items. Other states will incur a shipping charge.

Worldwide: Free shipping is available for Complete Headlights, Taillights, DRLs. For custom headlight retrofits, carbon fiber products, and performance products, there will be a shipping charge.  

Please note:
• For Retrofits, you are purchasing a headlight modification service.
• If you select "Shipping own headlights to BayOptiks for modification", you are required to send us your headlights.
• If you choose "Purchase new OEM headlights", we will order and modify a new OEM headlight for you.
• Once your customizations are complete, we will ship it to you!

• Complete Headlights: 3-5 business days for order processing plus shipping time.
• Custom & Pre-Built Headlights: 6-8 weeks depending on the complexity and component availability.
• New OEM and cores: 6-8 weeks plus an additional 4-8 weeks as these are special orders base on the vehicle VIN due to different versions (North American, European, etc.)
• DRLs, Taillights, Brake Pads, and Carbon Fiber Aero: 3-5 business days for order processing, plus shipping time.
• Lens Replacements: 1-3 weeks plus shipping time.

Please note, we do not have control over the time frames of our vendors, manufacturers, and delivery services as they may delay processes in regards to components and shipment.