I very much doubt there is a 'BS' for r.c. cars. I think the 'bs' that Chris mentions is the one that starts with bull and ends in sh**!
If you are looking for standards for racing specs for cars however then try the BRCA website
www.brca,org which has the 'standards' for all the various racing classes. i.e. minimum weights, maximum dimensions, allowable motor and battery lists (this is separate within the Electric Board section).
There are equiavalent bodies elsewhere around the world such as roar (usa)
http://www.roarracing.com/ and efra (europe)
http://news.efra.ws/ and ifmar (world)
http://www.ifmar.org/