Template page with changeable content

Hi,

Usually you use the ?product=iphone-4 in the URL to display an entry called iphone-4 and its’ rows content. I want to use one entry for multiple pages but just change the product name within that page.

I am designing accessory pages that will be displayed for multiple products whereby the wording is changed for each product using PHP. For example product description might read

“The <?php productname?> car charger is perfect for all cars.”

But because there will not be an individual accessory page it is causing a problem:

http://www.site.com/products.php?accessory=&lt;?php echo $productname?>-<?php echo $accessoryname?>

This link would be for accessories whereby they are compatible with multiple products.

So it would produce:

http://www.site.com/products.php?accessory=iphone-4-home-charger
http://www.site.com/products.php?accessory=iphone-5-home-charger
etc.

My problem is: Can this be done when the user manually types in the URL? What if some one types in:

http://www.site.com/products.php?accessory=iphone-4-home-charger

May be it would be best to use

http://www.site.com/products.php?product=iphone-4&accessory=car-charger
http://www.site.com/products.php?product=iphone-4&accessory=home-charger

I want to avoid using & in the URL as this does not make it friendly to remember. I want www.site.com/product=iphone-4-car-charger and www.site.com/product=iphone-3-car-charger all using the same information apart from the product names different. I want to use mulitple product entries (iphone3, iphone4 and iphone5) and one accessory entry (car charger). Then use the car charger page to appear representing all products (in this case 3 accessory pages for iphone3, 4 and 5).

what is the best way to use one page for many, whereby the pages need the product name changing for each accessory?

Matt.