The roof one has obviously been fitted at a later date..
I had a wing mounted aerial on my 1.6 CL when I bought it but I took the wheel arch lining out, cut the wire, then ripped the aerial off and put a grommet in the hole so I could fit a roof aerial.
Are you sure your wing mounted aerial is electric? As mine wasn't...
As for the water leak, do you have a sunroof? If so, check the drainage tubes located on the A pillar when the door is opened.