I thought it would be nice to have a cutting board over the sink to maximize prep area in my 2013 24R. I thought of cutting a board to size, then decided to see if I could find something suitable that fit. Since the opening in the counter was 15 5/8", and the sink edges were about 14 3/4" apart, I figured that any width in between those sizes would work.
I did a search on Amazon, and found this:
Amazon.com: Proteak Edge Grain Teak 15.5 x 12 Inch Chop and Slide Cutting Board: Kitchen & Dining
Best of all it was less than $10 delivered (with prime).