I have a '81 300SD with the original dark blue paint. You will for sure get color on your cloth when you wax the car; has always happened to me. I have tried Mother's and Meguir's sealer both without a lot of satisfaction.

When the rain dries on the hood it leaves white splotches which are very difficult to get out. I do not compound them out because I do not want to eat through the paint. That said, the white splotches never come completely out with polish and can always be seen. After a while the entire hood takes on the same cloudy color and it is time to polish it out again. Hood and trunk, not the sides which are perfect. Gave up on the top a long time ago; it is completely clouded and is therefore not too noticeable.

I just live with it.

How about some pics.