GRS20x electronic systems manual. Wiring guide parts diagrams etc. 
Its written in really shitty 2010 javascript which doesnt work in modern browsers
they also werent smart enough to use unicode.

Suggestions for runnings successfully :
Win XP SP2 VM
System Locale : Japan
Internet Browser : Internet Explorer

Im currently working on extracting and naming the EWG pdfs along with converting the site to run in modern browsers.
Check the following for updates : https://grs204.memecity.co/ (this may currently work in IE with compatability mode enabled)

https://github.com/Blizardy