I recently ordered a new set of headlights for the Dakota rather than trying to clean mine. I would like to recommend the merchant I got my lights from. The company name is Auto and Art. They have a number of locations around the country so delivery is pretty quick.
My situation was that I received my set of headlights and immediately installed them. I threw the old ones into the trash dumpster that was already at streetside because that was the day for collection. Later that night I went out to adjust the new ones and while adjusting the up/down of the driver's side, the adjuster pulled through the housing.
I contacted Auto and Art and got a reply from Amy. Amy wanted particulars of the problem and after I supplied her with the information, she told me they were shipping a new headlight assembly at no charge. I asked for return shipping information so I could send back the defective assembly and she told me to just throw it away. I let her know that I preferred to send it back and didn't feel comfortable with keeping it. She still said to throw it away. The new one should be here tomorrow.
Not often you get customer service like this. They have products other than headlights, too. Some of them are for Fieros. Give them a look-see.
http://www.autoandart.com/