It's called a zimmer ignorant. They are custom built rebodies by another company. I think there are a few here on the forum and I know there are guys much more knowledgable then me on the matter. I'm sure they'll chime in soon.
------------------ 87 GT....SBC...fast as hell... Proud new owner of....THE DIRTY RAT
Edit to add: IMO the Zimmer is the perfect candidate for a Caddy 4.9 swap. The Zimmer looks like an older luxury car, so an engine from an older luxury car would be a perfect fit. Plus, a car like that needs to have the V8 rumble to round out the image.
[This message has been edited by Blacktree (edited 04-05-2016).]
Just another tidbit that interests some. If you find one in the pick-a-part, check to see if it has the steering rack and power steering pump/lines in it. Zimmer added power steering to the Quicksilver and you can sell the system for a pretty decent return if you don't want to use it in your own vehicle.