As with legal malpractice claims based on negligence, in breach of fiduciary duty claims legal experts are typically called to testify. Expert testimony helps explain to a jury what the attorney should have done under the circumstances in question.
Bending is a metal forming process in which a force is applied to a piece of sheet metal, causing it to bend at an angle and form the desired shape. A bending operation causes deformation along one axis, but a sequence of several different operations can be performed to create a complex part.
A mandrel bent exhaust means the bends in the exhaust are smooth and do not neck down. A press bent exhaust has dents in the bends which causes a disruption in flow and isn't good for producing power. Many older cars have press bent exhausts, so a performance unit would give you a good boost in power.