Wordpress Rewrite URL from API NOT the database - php

Question

I am building a site using WP and the Prosperent API. I have built out product category pages where the user can see all the "Backpacks" and even sub categories. I now want to build product detail pages. Because the data comes from an API, and not stored in my database I don't have an easy want to have pretty links.
On the category pages, I am linking each product like this:
$pageLink = esc_url( add_query_arg( array (
'gearID' => $value['catalogId'],
'gearTitle' => $value['keyword']
),
'http://www.example.com/products/g/' ) );
Which looks like this:
http://www.example.com/products/g/?gearID=65198586171ee0ea97f3e39935468f4d&gearTitle=The%20North%20Face%20Inferno%20Sleeping%20Bag:%20-20%20Degree%20Down%20Asphalt%20Grey/Caution%20Orange,%20Long
I AM Successfully capturing the "gearID" & gearTitle query variables, This allows me to display the product on the product detail page template. This is working great. But the URL has my query strings in it.
I have tried several different variations, but this is my code for the rewrite:
add_filter( 'query_vars', 'add_query_vars_filter' )
function custom_rewrite_basic() {
$gearID = get_query_var( 'gearID', false );
add_rewrite_rule('^products/g/([0-9]+)/?', 'index.php/products/g/?gearID=$matches[1]', 'top');
flush_rewrite_rules();
}
add_action('init', 'custom_rewrite_basic');
You can see in the code I have a get_query_var for the gearID, I attempted to insert where $match[1] is placed and didn't work. Perhaps I need to store data in DB so WP knows what to rewrite? Can't do it on the fly?
Ultimately, I want it to look like this:
http://www.cascadegear.com/products/g/The%20North%20Face%20Inferno%20Sleeping%20Bag:%20-20%20Degree%20Down%20Asphalt%20Grey/Caution%20Orange,%20Lon