AST BMW F10 M5 Lowering SpringsGive your BMW F10 M5 the extra stance it needs with AST lowering springs. AST Lowering Springs are manufactured from a premium high tensile chromium silicone wire which is handpicked by AST engineers for its quality and metal consistency. Each spring is cold wound and then heat treated to increase hardness and reduce internal stresses present after winding. Each spring is then individually shot peened, phosphate treated, and then powder coated to