In RWD setups, only the rear wheels are driving the car forward. That means the rear tires need to maintain grip under acceleration, cornering, and braking. A low CG keeps the weight closer to the ground, reducing the tendency of the chassis to lift the front and unload the rear under throttle. More even weight on the rear = better traction.
Lower CG helps maintain even contact patches on all tires during high-speed cornering. Since RWD cars rely on rear grip not just for acceleration but also for balance mid-turn, this helps them carry more speed without sliding out.
This DT03 has been modified with low CG mounts and dampers:
More information can be found here: https://upgradeparts.com/2025/04/02/designer-series-tamiya-dt03-low-cg-damper-mounts/
