Since it is only a few products, categories, and pages, you should be able to pull this off with Apache's Mod Rewrite.
You can hand-write the rewrites yourself. They go in your .htaccess in the root of your website.
Here's an example I whipped up off the top of my head:
Code:
RewriteEngine on
RewriteRule ^/?cars$ /index.php?main_page=index&cPath=1 [L]
RewriteRule ^/?ford-cars$ /index.php?main_page=product_info&cPath=1&products_id=2 [L]
If you absolutely must have the ".php" on there (which I don't recommend), change it to this:
Code:
^/?cars\.php$
^/?ford-cars\.php$
Keep in mind that your links on the website would still show the old "main_pageblahblahblah.php" stuff. But you can give out some fancy looking urls this way, and quick. If you wanted to change how the website generated its urls for links, you'd have to edit the code, unless there's some other way I don't know about.