Tube - work also helps stiffen the chassis. (evo.co.uk)
For the Evo, engineers added bracing in key locations, such as behind the back seat and in the floor crossmembers to further stiffen the chassis, and strengthened steering attachment points and knuckles to improve steering precision. (Autoweek.com)
The team also stiffens the chassis, including adding a flexible V - brace in the engine compartment. (motor1.com)