1. Product Overview
This document provides instructions and information for the Audi Genuine Accessories Rear Diffuser, model 8K0071620C3Q7. This accessory is designed to enhance the aesthetic and aerodynamic profile of your Audi A4 Sedan.
The rear diffuser assembly includes outer pieces intended for body-color painting and a central section pre-painted in matte silver. It features an aluminum-look blade specifically designed for vehicles with left twin tailpipes. The complete set comprises the main diffuser unit and the blade.

Image 1.1: The complete Audi Genuine Accessories Rear Diffuser assembly, showing the main diffuser body and the separate aluminum-look blade.
2. Compatibility
- Vehicle Model: Specifically designed for the 2013 Audi A4 Sedan.
- Exclusion: This rear diffuser is not for use in conjunction with S line, S, and RS models.
3. Features
- Enhanced Aesthetics: Adds a dynamic and sporty design element to the vehicle's rear.
- Visual Impact: Contributes to a lower visual appearance, enhancing the vehicle's stance.
- Material: Constructed from durable materials, with an aluminum-look blade.
- Finish: Outer pieces are primed, ready for painting to match the vehicle's body color. The center section is pre-painted matte silver.

Image 3.1: A detailed view of a section of the diffuser, highlighting its surface texture and contours.

Image 3.2: A close-up shot of the diffuser's edge, showing the precision molding and potential attachment points.
4. Installation (Setup)
Installation of the Audi Genuine Accessories Rear Diffuser is designed as a screw-in process. Due to the technical nature of automotive component installation and the requirement for precise fitment and potential painting, professional installation by a qualified technician is highly recommended.
4.1 Pre-Installation Steps
- Inspect Components: Before beginning, carefully inspect all components for any damage or manufacturing defects.
- Painting: The outer pieces of the diffuser are primed and require painting to match your vehicle's body color. Ensure this is completed by a professional paint shop before installation.
- Gather Tools: Ensure all necessary tools for a screw-in installation are available.

Image 4.1: Various screws, washers, and clips included for securing the rear diffuser.
4.2 General Installation Guidelines
- Safety First: Always ensure the vehicle is securely supported on a lift or jack stands. Disconnect the battery if necessary.
- Remove Existing Components: Carefully remove the original rear diffuser or bumper components as per Audi service manual instructions for your specific A4 Sedan model.
- Position Diffuser: Align the new diffuser with the mounting points on the vehicle's rear bumper.
- Secure Fasteners: Use the provided screws and fasteners to securely attach the diffuser. Ensure all connections are tight but do not overtighten.
- Blade Attachment: Attach the aluminum-look blade to the diffuser as instructed in the detailed service manual (not provided here).
- Final Check: After installation, visually inspect the diffuser to ensure it is properly seated, aligned, and securely fastened.
Warning: Improper installation can lead to component failure, vehicle damage, or personal injury. Consult an authorized Audi service center for professional installation.

Image 4.2: The underside of the diffuser, illustrating the structural design and potential attachment points for installation.
5. Maintenance
To maintain the appearance and integrity of your Audi Genuine Accessories Rear Diffuser, follow these guidelines:
- Regular Cleaning: Clean the diffuser regularly using mild automotive soap and water. Avoid abrasive cleaners or harsh chemicals that could damage the painted or matte silver surfaces.
- Inspection: Periodically inspect the diffuser for any signs of damage, loose fasteners, or cracks, especially after driving on rough terrain or in adverse weather conditions.
- Waxing/Sealing: If the outer pieces are painted to match your vehicle, apply automotive wax or sealant as you would to the rest of your car's paintwork to protect the finish.
6. Troubleshooting
While the rear diffuser is a passive component, issues can arise from improper installation or external factors.
- Loose Fitment: If the diffuser appears loose or rattles, re-check all mounting screws and fasteners to ensure they are securely tightened. Refer to the installation section.
- Visible Damage: In case of physical damage (e.g., cracks, scrapes), assess the extent of the damage. Minor cosmetic damage might be repairable by a professional body shop. Significant structural damage may require replacement of the component.
- Paint Issues: If the painted sections show signs of peeling or fading, consult a professional automotive paint specialist.
For any persistent issues or concerns, it is recommended to contact an authorized Audi service center.
7. Specifications
| Specification | Detail |
|---|---|
| Model Number | 8K0071620C3Q7 |
| Manufacturer | Audi |
| Item Weight | 9.5 pounds |
| Package Dimensions | 68 x 20.5 x 6.3 inches |
| Installation Type | Screw-In |
| Material | Aluminum (blade), other materials for diffuser body |
| Auto Part Position | Rear |
8. Warranty and Support
Warranty information for Audi Genuine Accessories is typically provided at the point of purchase or through official Audi dealerships. Please retain your proof of purchase for any warranty claims.
For technical support, installation assistance, or warranty inquiries, please contact your authorized Audi dealership or visit the official Audi website for customer service contact information.
Official Audi Website: www.audiusa.com





