I guess when the glass roof of the Lounge is taken out of the equation (since both cars are the C), the remaining differences are:
- chrome trim under windows and on mirrors, bumpers
- seats, shape and material (more retro in the Lounge, more 'grey' in the S)
- instrument panel graphics
- door sill trim plates (not present on the Lounge but hardly a biggie)
- alloy wheel size
- climate control air conditioning or not
- steering wheel shape (S has flat bottom, buttons and Blue&Me seem to be standard on both)
Really quite cosmetic differences but not all of them can be changed - e.g. the chrome trim under windows cannot be fitted to an S without cutting/rebonding the rear side windows. So it's worth choosing the one you like best.
-Alex