It is possible, of course - but Škoda does not roughly recommend it (or DOES NOT ALLOW it) - the roof, which is intended for window installation, has a different construction than the "ordinary" roof (the times when it is on Fáček or Felina, or even on Š105 / 120, it didn't matter if they were already). By interfering with the construction of the roof, you will change the rigidity of the castle (especially torsion). And the question is, what would it be - possibly, "said" the insurance company (in case of injury, etc.).