In a product liability action against an auto manufacturer, alleging that plaintiff suffered serious injuries in an accident caused by a design defect in the speed control system of his pickup truck, the district court's entry of a jury award of damages to plaintiff is reversed where: 1) plaintiff's expert's testimony should not have been admitted; and 2) without any other expert testimony to establish that the truck was defectively designed and that there were safer alternative designs available that a reasonably prudent manufacturer would have adopted, the plaintiffs cannot prove their case under West Virginia law.