I found what I'm looking for. How do I delete certain vehicles from my search? How do I delete my account?
'Saved' searches have an X in the window to delete them. Recent unsaved searches you can get rid of by deleting cookies. As for deleting your account click the ? in orange in the lower right of this page and ask them there. You can also go to 'My account' then 'settings' then click the button that prohibits CarGurus from sending you emails. Now dealers that have your email may pester you for a while. All you can do there is ask then to stop sending them