Connect small wires to auto battery post?

I don't have a picture to show you, but before I added the auxiliary power connection panel to the coach battery, I went to the local auto store and they had these spade "Y" wire connector for top post batteries that the V part went under the thick battery cable and the other end had a screw terminal for lugs or wires. It's similar to what you are being shown above, but instead of a large battery cable clamp, it was a semi thick spade connector type with a second smaller post for attaching wires, spaded or ring connectors that didn't interfere with or required altering the original battery connector.

They also had a set that had two and three aux connections but at that stage, using a dedicated auxiliary power connection bar would have been better. If you have a side post, they had a similar set just for side post that had ring connectors instead of spade connectors.