Nobody wants to oversee that process. Especially since most people effected are teenagers that spent $80 on an amp.It would cost a substantial amt of money to test and confirm they do what they say. It would cost more if a consumer wanted to make a claim. And it would wipe out most of the entry level business in the industry if it were enforced.
Buying an amp that's cea-2006 certified is a good solution, although not every amp that's accurately rated subscribes to that.
The lesson is to know what you're buying before you get your wallet out...that applies to a lot more than car audio.
Either away from you or upward.
Just use a pair of y cables. I prefer 1male/2female
You plug the male end into the amp.
One of the female ends would connect to the rca coming from the HU.
The other female end would be the output for the 2nd amp.