I've fitted a Kyosho Shoot body from the Lazer ZX5 FS2. Needed to make a new body post at the rear and do some cutting on the undertray. Nothing difficult though!
I like this body a lot.
http://www.flickr.com/photos/mkoolmees/8609466157/
http://www.flickr.com/photos/mkoolmees/8609465603/
Hope the links work... The car may not look like a 511 but it is! It has the K big bores fitted, the K Shoot body and Atomic Carbon shock towers... ;-)