Found what I needed at the local KMart! It was the type with the adjustable bottom (to fit in the cup holder, it locks in place), and the adjustable top to fit every size that I need.
Works great, except for one thing....because of the cutout in the back of the cupholder (in the E, where the two cupholders "join" - apparently an attempt to allow spills to flow everywhere), I had to angle the new addition so it is slightly over the emergency brake. Hopefully, I won't need the emeregency brake, but if so, the cupholder will pop right off (I tried, just to be sure!)