Ridgeline Motorsport - GT4+ Aero Kit - BMW F8X M3/M4

Expected ETA: Late Dec 2025

Ridgeline Motorsport GT4+ Aero Kit is engineered for Maximum Performance. Inspired by BMW Motorsport. Proven on Track.

The Ridgeline Motorsport GT4+ Kit is our ultimate aero package for the BMW F8X platform—developed using the aesthetic foundation of the OEM M4 GT4 and evolved beyond GT4 rule-book limitations. By redesigning every component around real-world data, we’ve created a package that produces significantly increased downforce.

Designed to comply with GTA Street Class and GridLife Street Mod regulations, the GT4+ Kit brings professional-level aero to the enthusiast and competitive driver alike.

Proven Track Performance
The whole Kit is designed to optimize performance for vehicles with bolt-on molds only. The test results are based on Road Going F8Xs with no weight reduction with 275/35/R18 200TW Street Tires Only. F-Chassis Testing Results to Date:

• SuperLap Battle 2025 – COTA: P3 – 02:22.320 (Fastest BMW in class, excluding 2 Supras)
• GridLife 2025 – Laguna Seca: 1:35.341
• Global Time Attack Finals – Buttonwillow CW13: P4 – 01:50.940 (Fastest BMW in class, excluding 3 Supras)

Real results. Real podiums. Real validation.

Included Components

GT4+ Front Lip
A reinforced, GT4-inspired design that creates a sealed front plane when paired with the splitter. Can be used without the splitter, though lifespan will be reduced.

GT4+ Tunneled Splitter

• Two-piece lip + splitter system
• Integrated airflow channel for the lower oil cooler
• 1-piece molded tunnel for increased downforce and rigidity
• Optional aluminum skid block kit
• Includes all hardware; minor OEM chassis modification required

OEM GT4 1:1 Canards
Exact GT4 geometry for improved front-end bite and increased mid/high-speed stability

GT4+ Rear Wing
Redesigned chassis-mount solution eliminates the water-leak issue found in the OEM GT4 wing

• Maintains OEM structural strength
• Larger foil than OEM GT4 (no GT4 rule limitations)
• More rear downforce with similar aerodynamic efficiency

Why Choose the GT4+ Kit?
Inspired by BMW Motorsport, engineered for maximum performance. 

• Increased downforce front and rear
• Balanced aero for serious track performance
• Legal for popular street-class time attack series
• Modular system—purchase as a full kit or individual components

Full kit recommended for best aero balance

• All hardware included
• Splitter skid blocks optional
• Professional installation recommended