The Menards cars are exactly the size of a scale 40' boxcar, the only difference is the width is about 3/32 narrower. If you have a scale boxcar, put it behind and you'll see what it looks like. I also like the Menards cars are closer coupled than others, makes them look even better in a string.
I posted a review of the Menards cars not long ago.
Review: Menards Reading Boxcars
Here's the thread where I posted the pictures of the comparison to the new Lionel Vision Line PFE Reefers.
RE: (07/02/15) O Gauge Release
Here's the shots from my post.