You could have the best suspension set up and it would be pointless without the Suspension arms. Suspension arms are what connects your suspension setup to the chasis of the car. Needless to say this is one part you don't want to skip on. In addition to its basic function of tying the system together, it improves the ride of the car with firmness unavailable in stock set ups.
The suspension bar is a key component to increase the ride and drive ability, it accomplishes this but reducing the amount of roll (or body roll) of the car. A suspension bar keeps the car's body flat by moving force from one side of the body to another. Perfect for smoothening your daily drive or giving a firm solid feeling while taking corners at the track.