My car was built to order. It's a month old Skoda Ooctavia Estate. With the cold weather, two large suction cup marks (circle with a central circle dot) appear - then disappear once the interior fan is on. The marks are textured. I've tried Autoglym glass polish (they show up when this is applied). The dealer also had their valet try, but the marks in the centre of the inside of screen will not budge. What could they be and what could remove them? I've asked the dealer to speak with Skoda UK on factory installation methods.