A rail assembly for a motor compartment of a motor vehicle having a bumper and a deformable energy-absorbing device secured rearward of the bumper, includes a longitudinally-extending motor compartment rail operatively connected rearward of the energy absorbing device and having an inner rail member and an outer rail member configured to define a cavity therebetween. A stability enhancement member transversely spans the cavity and is secured to both the inner rail member and the outer rail member.