Auto-Rx and synthetic factory fill

[ssj4]

OK, I have attempted to read the forum posts and the auto-rx website for this info:

I just ordered some Auto-Rx for my '95 M3 which of course still speced dino in it's day. But what about newer cars with factory spec'd synthetic, i.e. the rinse phase?

 

[Weasel]

I believe you can use a hydrocracked "synthetic" Grp. III which meets the required BMW specs, but does not contain PAO's or esters which can interfere with the rinse phase.