ergophobe - 1:57 am on Feb 11, 2013 (gmt 0)
In some cases you can simply point to the same physical page as your custom 404.
Yes, you can point to any page - a custom page with a search box might be good. A page that grabs key data - make/model/year and lists the next closest stuff you've got would be even better I think.
Just be absolutely sure that the response header is a genuine 410.