The msds says meguire’s #7 is composed of Light distillate 10-20%, Diatomaceous Earth 4-8%, Hydrotreated Distillate 5-10% Glycerine 1-5% 43% max listed ingredients the balance is likely inert (water).
I know nothing in that composition that will penetrate acrylic paints. Rather the distillates are there to dissolve oils and old wax, the DE is like clay and is a very mild abrasive, the hydro distillate is basically paint thinner same purpose as the light distillate and glycerin gives the ingredients the abilty to stay combined and offers some body to the mix.
Once an old car’s paint is clean (wash with detergent, clean it with meguire’s #7, or any other solvent that cuts grease and oil), start polishing and finish with wax.
We’re on the same page, just different books.