[1795]

I have not had that problem, and I have driven my ERA at 75 mph with just the soft top and no side curtains and did not have any oscillation. You could see that without the center support that the top would try to pull the center of the windshield up. The oscillating has me a little concerned and makes me think that the supports on either side have come loose. You may want to check the side supports. Take a look at the bows as well. How tight does the top fit?