Like you, I am very impressed with Auto-RX. I am also impressed with this site. I think this is perhaps the only site on the internet where a person can obtain good information about motor oils, additives, oil filters, etc. I have never used a BG supplement for transmissions, but I have used BG fuel system cleaners. As far as I can tell, they work. However, several people at this site seem to be impressed with Neutra for cleaning fuel systems and also Amsoil fuel system cleaner. I am thinking about ordering Neutra, which can also be put into the oil. I have heard that Lubegard automatic transmission supplement is supposed to be really good, approved by some new car makers, and I have noticed it available at some automatic transmission shops.