»Where do the ETM cheats come from?«

Sorry i fthis has been asked before, but as you can imagine, askingabout ETM cheats in any search bar including this forums, results in simple pages of cheats. this isn't what I want to know.

What I was wondering, is where are the ETM cheats located? I know that some are hidden with the freeway chase scene in Reloaded, and i know that some are even hidden in Soundtracks. I'm not entirely sure why I want to know. I'm gonna assume I'm just curious as I've always been fans of Easter Egg style things.

Either way, if you have any info regarding what cheats are found where, then you'll have my eternal gratitude. Thanks anyway.

I have the strategy guide, and I know loads of em origionate from there. I had no idea that there are some in the OSTs and cutscenes. WOW! These games just continue to blow my mind...