Tailgate Seal...Buy one or make one?

I have heard that the tailgate seals sometimes don't seal all the way up, or arn't as thich as they should be or the sticky stuff doesn't stick to liners very well.

Any ideas?

 

I just put seal that came with my tonneau cover on. From the looks of it very similar results could be had with foam or rubber weather stripping from the hardware store.

I think I might have to fill in a few gaps with extra pieces of the sear or weather stripping.

I don't expect it to be as air tight as a submarine, just want the majority of the road spray out.