Yeah, you are right! the quarters have to be trimmed esp. the lip in the wheelwell, If you cut the rust out and put them over top they fit good, I would never do that, I've seen some guys do that, so be aware! With careful trimming and some creative fitting they look good installed. They saved a lot of cars, so maybe we should be thankful that they are available, even if we cut out patches and use what we need, they're still a bargain as opposed to the hand formed ones we had before! :-D