Gona be doing a drain and fill on my 7AT... Not going to be using the Matic atf, going with amsoil...

My question, is it okay to mix both the fluids?

 

Not sure on the G, but with my Acura TL we did a 3x3 meaning you drain the ATF 3qts at a time 3 times. So, drain, fill with 3qts, drive around the block, drain, fill 3 more qts, drive, final drain and fill. Probably does not replace ALL of the fluid, but you get the majority of it.

 

What he said
https://www.myg37.com/forums/d-i-y-i...rop-clean.html

 

You probably can but the point of the flush is to get any metal particles from the trans out and like oil, the functionality of the fluid loses its effectiveness as it gets older. Its best to fully change it. In a pinch you could mix them and change it later but I wouldnt do it as a long term thing.