A nice article that touchbases on the Ferrari 400 as an investment. I will add this article to the online section. Unfortunately it's not in English, while their website can be viewed in English though. So you need to whack this link into Google translator. Even the majority of the commentors are in favor of the 400 - that's unusual.
If you fancy this picture, it's taken from the magazine, The Ferrari story nr 2. It's available in the download section: magazines.