Guys, did they even have clear coat paint in the 1970's?

My dark blue 81 300SD has given me fits over the years with water spots. It is a single stage paint and I have lightly compounded it at least four times over the last four to five years. It helps but it does not take out all of the water spots (in fact it just makes them a little less noticeable) and I am afraid to keep compounding. Just might try some of your vinegar et al approaches. I asked this same water spot question about a year ago but did not get nearly as many good answers/suggestions as this thread.

It is also beyond me why I can have fresh, new wax and somehow overnight just rain on the hood can create a disaster of water spots. How does it get through all that new wax?????