You'll find a lot of Regal info on

Here
BonnevillePro.com
Forceovermass.com
RegalGS.org (the current software is brutal on most browsers)
3800Pro.com
Some on CGP, but sometimes it helps to lie about owning a GP for help.

What are you looking for specifically? Many of us have great knowledge and the one or two areas that are specific to the Buick are easily covered by one of us that owns one. (Like me)