I have just installed the molding on my RX270 (a 3rd gen RX sub model available in many countries but not in North America). I do not have the 3M solution as well so I just used regular alcohol I bought from the pharmacy. I believe it is able to remove the layer of wax just as effectively because the molding sticks on my paintwork like super glue. I recall watching a Youtube video of someone fixing the molding on his LS and he used rubbing alcohol to prep the surface.
Once the molding is in place, I applied some wax on the molding and the surrounding paintwork that was earlier stripped of wax by the alcohol.
I like the look of my car with the side molding so much better than the original bare look. Gives me peace of mind when I park my car next to another.