I would call the siding company, any siding company and ask them what they recommend. Good luck.

Try this:

Here is a link that might be useful: http://www.finishing.com/280/59.shtml

Thanks, CC....my husband ran across that link late last night.....the Works will be our plan today....hopefully we can find it locally! Will update this post after we use it.....

My favorite go-to is Bar Keeper's Friend. It's kind of like comet or ajax, but not as abrasive and it works on vinyl. I use it on my fiberglass kitchen sink with excellent results. I would try it on a small spot first. If it doesn't work just with a bit of elbow grease, make a paste and let it sit on it for awhile. Definitely try it on a small spot first. I've never used it on vinyl siding. I hope this helps.

Yay! The Works did the job! The vinyl company also suggested using this product....whew! Thanks! :)