Name that part!

Hi Fellow Boggers,
can anyone tell me the name of the removable white plastic strip which is used to cover the joining screws etc. between the vertical sides and the roof of the BT. By this I mean the two strips of plastic that run the length of the van - up the front the along the roof join and then down the back. Somehow I have damaged one of the strips and naturally I am looking for a replacement.

Also, where I might buy a replacement length (I will probably do both side lengths to maintain colour consistency).

cheers

Searenity