Add time to existing subscription with new product key

I tried to find this suggestion, but did not find this exact one in my searches.

 

It would be nice if when 'renewing' a current subscription with a new product key, as opposed to the Norton Renewal process, that the time remaining on the old subscription were automatically added to the new time for the new key.

 

As it is usually less expensive to purchase a new product and key than a Norton renewal, many users choose this option.