a friend has me some 18" tsw rocket black alloys they are fitted to his 2004 e class merc will they fit my superb

They will go straight on, however you really need a set of spigots to change the center bore from the Merc's 66.6mm down to Skoda's 57.1mm, this is the center part of the disc/hub that the wheel locates onto.

Being non OEM Merc rims check the offset is between ET 35-38mm for piece of mind.

E Class W211 after 93

5x112

35 to 38 (offset - ET)

66.6 (bore)

Superb after 02

5x112

37 to 38

57.1

Gizmo is spot on but I would check the ET carefully as most Merc wheels tend to be a higher ET from my experience which causes problems and may require spacers.........