NJ it could be a MPG thing also for CAFE. as Wt. is the enemy for that & even a tiny bit of % increase in MPG X the # sold in a year makes a big diff. It also allows performance models to be sold in that same model, but it's the corporate average that counts overall. I had a Ford Festiva that was noisy on rough pavement in my younger days so I just drove faster for less time on the road , plus it didn't hurt MPG much. Used the stereo for sure to drown out the noise! Maybe another soln is an electronic noise cancelling system as used on some new GM vehicles and maybe others! It uses the existing speakers I would imagine!