If you use the EasySearch YMM app, and you upload a product to your store manuall, you will need to follow a few extra steps in order to get that new product to show up in the YMM (Year-Make-Model) widget.
First, download a fresh copy of your YMM database, by following the instructions available Here for the Turn14 app, or Here for the Slingshot app.
Then, open the downloaded file in Excel, Google sheets, or any other spreadsheet program you use, and find the vehicle that your product fits. In this example, we will be adding the product SKU "TestExample" to the fitment for a 1969 Chevy Camaro RS.
Add your new product to the "URL" column, in a comma separated list. As seen here.
Once you've added your part to the matching vehicle, save your changes, and upload the file to the EasySearch app.
Make sure to keep the edited CSV somewhere safe! Your changes can be overwritten by the EasySearch app or the Turn14 app at times, so re-uploading it may be necessary.
And that's all there is to it! Your new product should now show up under the YMM search for that vehicle.