create dynamic pages

Question

I have a website with about 200 accessories for a certain type some cars, the accessories are set up as normal products within Magento. However, the cars are stored in a new table within our Magento 2 database and we wish to list these within the website through the CMS pages.

. . I've created 7 empty categories to run alongside my shop:

• Cars (ID 1)
  • SUV’s (ID 2)
    • Brand A (ID 3)
    • Brand B (ID 4)
  • 4X4 (ID 5)
    • Brand A (ID 6)
    • Brand B (ID 7)

Within design/frontend/myvendor/mytheme/Magento_Catalog/layout, I've then created xml files for those categories to call:

• catalog_category_view_id_3.xml
• catalog_category_view_id_4.xml
• catalog_category_view_id_6.xml
• catalog_category_view_id_7.xml

Each file contains code similar to this:

<view xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Config/etc/view.xsd">
    <referenceContainer name="main.content">
            <block class="Magento\Framework\View\Element\Template" 
                   name="guns.ddcat1" 
                   before="-" 
                   template="Magento_Catalog::html/all-cars.phtml"
            />
        </referenceContainer>
</view>

Within design/frontend/myvendor/mytheme/Magento_Catalog/templates/html we have a file called all-cars.html whereby it connects to the external database and then displays all the cars for that category at the following URL’s

• example.com/cars/suv/brand-a/
• example.com/cars/suv/brand-b/
• example.com/cars/4x4/brand-a/
• example.com/cars/4x4/brand-b/

That works fine up to this point and all cars are displayed on the correct pages. The following part is where I’m stuck…

I now need to view each car in detail. As the car list changes on a daily basis, we need dynamic pages, so I was going to make each car clickable…

• example.com/cars/suv/brand-a/car1
• example.com/cars/suv/brand-a/car2
• example.com/cars/suv/brand-a/car3

I struggled with this, so as a simpler (but ugly) approach, I thought I could append the category with a variable:

• example.com/cars/suv/brand-a/?carID=111
• example.com/cars/suv/brand-a/?carID=112
• example.com/cars/suv/brand-a/?carID=113

Then in all-cars.phtml, we could then listen out for it using the following code:

if(isset($_GET[‘carID'])) {
    //connect to database and show specific car
} else {
    //connect to database and show all cars
}

However, when I try this, the carID= is treated as a new sub-category, hence catalog_category_view_id_3.xml is not listened to and as a result, all-cars.phtml is not called whatsoever.