2008 GS450h Body Panel problem

[matt_sabre]

Hi, I have a problem with a part of the bodywork coming loose and lifting up. It's the long thin piece that runs from the hood to the trunk above the doors. It works loose at speed and if I go througha  car wash...which is very annoying. There is no visible problem as the clips all seem to be in order and I can bang it back in place. I even had Lexus check it out but hey said they couldn't find anything wrong yet the damn thing still keeps working loose.

 

I went through a car wash today and I think I may have made it worse. It doesn't fit back completely now so I think I'm looking at replacement. Does anybody know what the actual part is called, where I might find a new one, and anything else that might be the cause or a fix?