I'm not sure if NHTSA gets involved with poor designs that result in monetary losses. Have you looked at the form? They are more interested in the SAFETY implications of the poor design. You'll have to play up the safety angle. Make sure you mention (perhaps stress) that failure can result in the car suddenly stalling in traffic. Stalling in traffic is the basis for many recalls.
95 E320 Cabriolet, 131K