Is it no 3 as Ronnie suggests? In that case I don't have one but I have repaired those now and again when they have split. I use Evo-stik Impact adhesive. If need be I glue a bit of inner bicycle tyre tube inside the seal.
I know a couple of people currently breaking 8-series cars. Do want me to find out if they have these seals? Just to be precise: you are talking about the left hand side of the vehicle, right (the term 'passenger side' is not well defined since there are both LHD and RHD versions of the cars)? Also, please confirm which number on the drawing Ronnie posted you need.