The unibody frame construction of most cars on the road today are essentially six-sided boxes (albeit with some large holes in them). This shape tends to offer a fairly rigid structure wherein all the forces that act on the body are met without allowing the body itself to distort. The Spider (as in all open cars), on the other hand, since it has no top, has a unibody that forms an unreinforced five-sided box . This structure significantly reduces the chassis's stiffness. When traveling over bumps and/or cornering hard, the flex developed allows unwanted relative movement of all of the suspension mounting points. In the "motoring" press this is usually referred to as "cowl shake" or "cowl flex". By literally allowing the suspension's mounting points to move relative to each other, handling precision is significantly reduced.
Adding the Chassis Stiffener's box section to the Spider's open unibody construction in essence ties a six-sided box to the Spider's five-sided one, and significantly reduces the Spider's open chassis flex. This gives much more precise handling, and results in a much smoother, quieter ride.
The chassis stiffener will make a substantial improvement in your Spider's handling and ride, yet is unobtrusive, and does not interfere with the appearance of the car.
Please allow two weeks for delivery.