Billet Aluminum Rear Subframe Insert Kit, B9/B9.5 Audi A4/S4/RS4, A5/S5/RS5

034Motorsport Billet Aluminum Rear Subframe Inserts, Audi A4 B9

The billet aluminum rear subframe insert kit from 034Motorsport is a simple yet impactful upgrade that significantly reduces unwanted movement in the rear axle, resulting in sharper and more predictable handling – especially during cornering and hard acceleration.

From the factory, the B9 Audi A4’s rear subframe bushings allow a fair amount of flex, which can lead to vague or unsettled handling. These precision-machined inserts reinforce the structure without the need for extensive disassembly. They simply slide into the existing bushings and tighten everything up where it matters most.

Machined from high-grade 6061-T6 aluminum and finished with a sleek anodized coating for durability and corrosion resistance.

Key Features:

• Stiffens the rear subframe bushings – reduced flex, better response
• Manufactured from 6061-T6 billet aluminum – lightweight and strong
• Durable anodized finish – looks clean and resists wear
• Compatible with factory bushings – no subframe removal required
• Improves handling, especially on tuned or lowered vehicles

Installation Instructions:

Download installation guide (PDF)

Vehicle Compatibility:

• Audi A4 B9 (all models, 2017–2023)
• Audi S4 B9
• Audi A5 / S5 B9 (verify rear subframe type before ordering)

Note: This product does not replace the original bushings, but works as a precision-fit reinforcement inside them. An ideal choice for daily drivers and performance builds alike, with no sacrifice in ride comfort.