Lately I have been considering getting a 108 car display case to house my favorite GM/Ford/Etc. cars. I was doing some research today on the internet and found that nobody seems to make them with slots that are long enough to accomodate some of the longer cars,so I think I might have to go with a case with straight shelves and no dividers. Does anyone own one like this? Do the shelves have a tendency to bow over time?