BMW G90/G99, M5 Carbon Fibre SQ-B Style Rear Diffuser

BMW G90/G99 M5 Carbon Fibre SQ-B Style Rear Diffuser

This is the most substantial rear treatment available for the BMW G90 M5 and G99 M5 Touring, a full SQ-B Style diffuser in 100% dry carbon fibre that reshapes the entire lower rear of the car rather than simply adding a panel to it.

Where a bolt-on diffuser sits under the existing bumper, the SQ-B design replaces the lower section outright with a deep, sculpted multi-piece structure. The result is a rear end that reads as a factory motorsport variant rather than an accessorised road car, with far more depth and shadow than any add-on can produce.

Every piece is 100% dry carbon fibre in gloss black, autoclave-formed and finished so the weave runs cleanly across the complex surfaces where the strakes meet the outer sections.

This is the halo option in the G90 range. It costs more and takes longer to fit than a bolt-on, and it is aimed at an owner building the car properly rather than adding a detail.

Key Features

100% Dry Carbon Fibre

Genuine dry carbon throughout with a gloss black finish, not a wet-lay or hydro-dipped imitation.

SQ-B Full Replacement Design

Replaces the lower rear section rather than mounting over it, producing far greater depth than a bolt-on diffuser.

Multi-Piece Sculpted Structure

Separate outer sections and centre element combine into a single deep, shadowed form across the full width of the car.

Gloss Black Finish

A deep gloss clear coat that holds its depth and resists yellowing.

Moulded to the G90 Bumper

Formed to the exact contour of the car so the outer edges follow the bumper line precisely.

The Halo Rear Treatment

The most aggressive rear option available for the platform, for a build where the rear is the focal point.

Styling Benefits

• The most dramatic rear treatment available for the G90
• Genuine depth and shadow rather than a flat add-on panel
• 100% dry carbon construction
• Reads as a factory motorsport variant
• Pairs with the SQ Style front canards for a matched kit

Vehicle Fitment

BMW G90 M5 Sedan (2024+)
BMW G99 M5 Touring (2024+)

Please Note

Professional installation is required. This is a multi-piece replacement for the lower rear section, not a bolt-on panel, and it takes considerably longer to fit than an add-on diffuser.

Carbon fibre is a natural woven material. Minor variation in weave pattern between pieces is characteristic of the material and not a defect.

Made to order. Please contact us to confirm current lead time before ordering.

Why Choose Proven Performance Parts

We specialise in high-performance parts for European vehicles — including Volkswagen GTI & R models, Audi S/RS platforms, and BMW M vehicles. Every product we offer is carefully selected for its quality, fitment, and real-world performance — tested by enthusiasts, for enthusiasts.