Your going to have something like this for your "new arrival" picture link:
And then on the inventory.php page you have your iframe.
Something like this:
The only thing with this code is that you must fetch the id value from $_GET["id"]
when you get to the new_vehiclelisting.php page.
So if your using like $_POST["id"] then you can load that variable like this:
This of course only applies to the new_vehiclelisting.php page.
Or, for your "new arrival" picture link, you could have something like this:
This would allow you to put any value you want for the id.
Then you would use this code for the inventory.php page: