In my experience Soma can even create some closed eye visuals. Two or three Pain-O-Soma 500mg puts me to sleep or out of my mind. Doesn't do a whole lot for my back pain, Tapentadol does a better job at that.
I believe so..."Low dose aspirin also showed an induction effect on CYP2C19." Which should mean an increase of meprobamate as a result of increased speed of metabolization. Either that or the other way around. So it could also mean that aspirin decreases the speed of metabolization of soma into meprobamate resulting in a greater effect from the soma.
I could be wrong so please correct me and of course do your own research.