This is where I learned that it was best to cut the panels 1/4 inch wider (wall to wall), and put the vinyl trim on each edge. You can see that the closest panel has no trim on it, and is a bit short. It is inside the cabinet however and does not show. But you can avoid the error with the slightly larger panel and the vinyl trim. Also note how the holes were cut large and to the outside for the cabinet bolts that go into the riv nuts. In this photo the ceiling is held in closer contact temporally with large washers and 1/4 inch bolts. The final trim and upper cabinets will pull everything into place.