A LEGO version of the Ghostbuster's ECTO-1 car, along with minifigs of the four buster's, was recently promoted from fan-made project to official kit.  http://lego.cuusoo.com/ideas/view/36088  I of course will be keeping an eye out for it.

However, like many others, I was disappointed the HQ building (shown in the above link) was not part of the kit.  Brent Waller, the creator of this project, heard the cries and released a free "blueprint" of his building using the Lego Digital Designer.  http://www.eurobricks.com/forum/index.php?showtopic=92672  Nice!

I've attached a copy of his plans to this message in case the original link ever disappears.