If the info is good does it matter who posted it? If the member has left the forum then better it say removed user than have some poor sod, waiting ages for a reply to a pm.
I don't want to tell you guys how you should or shouldn't run the site you do a damn fine job and I've never known a car forum to run so well. Just a suggestion that this may become a problem in the future as the media and press continue to rant and rave about data use and Internet privacy, making people more aware of their rights.
Generally the odd person might deactivate their account but I think many members will keep registered on the basis of not knowing if they might need to come back in the future, I think probably am still registered for sites I quit 10 years ago ?