A side panel of a cover which can be folded out through a roof opening in a vehicle roof, said side panel being adjustable between a lowered starting position when the cover closes the roof opening and a raised covering position when the cover is folded out, wherein provision is made according to the invention that the side panel, in the lowered starting position thereof, is arranged below a boundary or contact region between a side edge of the cover and a roof part adjoining the roof opening and at a distance from the cover.