What is your approach to dealerships as far as sold items is concerned?

What is your approach to dealerships as far as sold items is concerned? I noticed the particular software vendor had a straight up dead sitemap on both sites so there was that. Then there was 404 pages in index likely relevant despite updates to one of two of their sites. When something is expired in a high volume situation isn`t it best practice to redirect the page to relevant categories so people don`t come to nothing? I mean even assuming something is gone people can still see value by being redirected to a similar page. Even if there is mass volume of random products you can hold certain pages in redirect for a period of a month or two before removing the redirect pages from the redirect file (.htaccess) for expired products/sold/deleted pages.I know big ecommerce just says a product is sold out but it would be more valuable to upsell relevant product for sold out items.