Hi EJB, thanks for the reply. Yes they do have a small stopper at the top. The sun is on them at the moment and they are slowly clearing. Have also emailed company as still under warranty. If all else fails will try that.If the window has a small plastic stopper...remove it and warm the window until clear....replace stopper.
Thanks, will give it a tryAs ejb says remove the vent plugs even when the sun is on it and should solve the issue