This plugin is more about instructions than files as the files are actually just a define pages set. The Google programmable search is a great addition to the Zen Cart default search. The settings for the search are set up at https://programmablesearchengine.google.com and all you have to do is insert the code snippet into the define page. I have included suggested text and instructions for optimizing in zen cart.

Since it is only a new define page and not new code, this should work in all versions of Zen Cart, but I only tested it in 2.0, 1.5.8 and 1.5.7.

I had intended to do a database pull for the id number so that it would be even easier to install but so far Google has proved very problematic by turning off the working search permanently for the several sites I have worked with so far. If anyone is interested in this, please contact me and I'll be glad to provide my working files so you can play.

As soon as the contribution is accepted, I will post the link here.