An unused D40 would be of interest really only to someone with a concours car for show, and should fetch decent money. I've just replaced D40's on my 3dr and the difference is like night & day. The old tyres had no grip whatsoever even in the dry, and were bordering on outright dangerous when there was even a hint of dampness on the road.
Thinking about it, I might even know someone who's after one.