I've done a few trials with it but not a full car so I can't comment on trim staining. One observation is that its *very* oily so it might not, but don't take that as gospel.
MPP is very easy to use with no learning curve...just apply and polish away. What you'd expect from something that *must* be very consumer friendly. Very forgiving.
But some tips to get the most out of it.
MPP alters its aggresiveness dramatically according to pad choice. So to remove bad marring use a yellow pad or to just give it a gentle polish and great gloss use a green pad. Its an all-purpose polish.
Use the same as other polishes, except that you need to work it in well. It hardly dust, if at all, and won't dry while your working it. Don't be scared to work it in, once its broken down, until it goes clear and starts to remove itself. At this stage use light pressure because your only 'burnishing'.
The easiest way to remove the residue is to let it dry, unlike other polishes. It wipes off as easy as a sealant. it leaves the finish slick and slippery like its just been glazed (*I* believe it has).
The only negative is that its a royal PITA to clean the pads because its so oily.