My car is an '87 Euro 300D, and the rear doors won't fully open, probably due to non use. They seem to seize at halfway open, and difficult to close too from halfway open position.

I've been told that the problem is on the door stops. Do these fail due to non usage. Do I have to replace them, or can they be greased up?

Thanks a lot.

I think you may be talking about the door straps. They are less than $15 and PartsShop should have them. Easy to replace once you have the door skin out.