Thank you Victoria,
I tried putting the code in both Quick CSS and the custom.css with no change.
I do not have any caching plugins activated and viewed the page in safari and chrome. The big image still has a solid background.
Regarding above comment: Each grid row should display from 1 to 3 wheels to the right of each logo. The row next to the “Ultra Trailer Wheels” logo is bumping the second and third product onto a second line. Same thing with the last product row (Platinum Wheels).