I had some rust in my trunk area, but it was located in a thin strip all along the rear of the tail panel. i am going to cut that out and lay a peice in there. I also have rust right along side the inside wheel wells, and those can be cut out and peiced back in. My trunk extensions are in worse shape, and i had to replace one of them. I would say that after you clean up the surface areas and see what you have, if you have some thin areas all the way around the trunk area similar to what i have, i would replace the whole pan. I am trying to blend in the repairs, but some of those tight angle areas are tough. If i could do it again, i would buy a complete trunk pan and be done with it.