Thanks for your suggestion neileg but I wanted kind of a "clean"/ "structural" solution... like adjusting the softtop compartment or... hit the right side of the car against a concrete wall ()

It would help to know why/how has this distance difference arised in the first place. Does anyone noticed if it has also differences in the distances between eft and right sides of the car?

Neileg, if I trim the plastic its finishing will be different (different color/ brightness). I'm the kind of guy my friends call "obsessed" in having the car in perfect conditions, if you know what I mean...

Other thing I also thought about is to glue the bottom part of the rubber, which, I think, will force it to fit properly upon closing the softop compartment.