Novas PC-108 & Plexus work well for their intended purpose, cleaning or polishing acrylic (plexiglas). Note that the plastic windshields on our Hondas are not acrylic (which polishes well but is relatively brittle), they are polycarbonate (trade name Lexan), which does not polish well and is nearly impossible to remove scratches from. So why do they use polycarbonate? It's darn near indestructible and will not split into shards to trash your body in a crash. Polycarbonate is wash with water and dry with microfiber etc.
303 serves a different purpose, to UV protect and restore color and luster of plastics etc. I use it on the roof of my Honda S2000 convertible and on its dash etc. I think you'll find it very good for keeping the plastic interior looking new - is does on my 18 year old Honda.