The BMW 3 Series cars are well known for their agility and superb handling. However, because of the chassis design, there is a weakness in the 3 Series cars. The front shock towers are not well supported in the 3 Series chassis. In fact, they are somewhat isolated and unsupported. As a result, the towers can bend and flex under heavy cornering. This flexing can cause detrimental changes in the handling of your car, because, in general, the stiffer the chassis, the better the handling of the car. Camber strut braces are designed to maintain the distance between the shocks under heavy cornering. A bar linking the top of the shock towers ensures the towers do not bend when the chassis is flexing.
The best strut tower braces are one-piece units manufactured out of thick, welded steel pipe. These braces offer the best protection against chassis flex when installed between the two strut towers. ...
The one below although not as attractive, this brace is probably the most effective. The thick, large-diameter steel pipe directly reinforces the shock towers and requires significant forces to deflect and bend. Despite the two rather large angles in the brace, the strength of the steel pipe should compensate for the reduced rigidity. This is the type of bar which recommend if you want to install one in your car....