There doesn't appear to be a designated support thread. The thread started by Woodyman which was more of a news alert became the official thread but has the wrong title.

Here is the original thread: http://www.zen-cart.com/forum/showthread.php?t=37317

I've made two minor contributions:

v1.3.4 (added to contributions; should be available soon) - added "mpn", removed "label", fixed "product_type"
v1.3.5 (currently testing before uploading to contributions; available for download from my website) - added special prices

The script was originally written by Andrew Berezin and he can be contacted through his Zen Cart account name: a_berezin
Please note that he is no longer providing support for this contribution and any problems with installation etc will have to be addressed by other members in the Zen Cart forum.

I know that v1.3.4 works as I've been using it for quite some time. There may be issues with v1.3.5 so if there are any bugs with the use of special prices specifically, then please post here.

Ideas for future updates:

- Google Base specific product types:

Currently product_type is the string of categories and subcategories that your product is included in on your site. This doesn't seem to be a problem and actually helps with Google Base search results as each category name in the product type becomes searchable. For example, if you sell a Samsung monitor located in Monitors -> LCD on your website, the product_type would be "Monitors, LCD". Both the word MONITORS and LCD are searchable. When Google becomes more picky about product_type, an admin customization for specifying a Google product type to each product will be necessary.

Some tips for best results with the Google Froogle Feeder:

-Change the length of your product titles in your SQL database from 64 to 75-80. Google Base allows up to 80 characters and this will greatly increase your products searchability. I find that more than 75 characters does not look good in the default Zen Cart however.

-Run a cron job for currency updates a few minutes before the google froogle feeder. This will ensure that your prices posted on Google are the same as your website if your default currency is not USD. As a Canadian seller, this was a personal issue for me.

-For your product's model number, use the specific MPN supplied by your manufacturer for best search results. Other model numbers can be placed in your products title.