Any "headlight restoration" will always tend to look bad in short order--if only because the UV protectant that was previously on the lens, is now gone. Getting some type of coating/protectant on the lens...after you clean it...will help with longevity.
On another note, mine were also starting to go hazy when I got it. Rather than cleaning them, I installed some CF light covers & brite-*** LED's (mostly to counteract the light attenuation from the covers). Works like a dream.
