I recently encountered a problem in getting a truly high gloss shine on a plastic model. I had used Halfords Plastic Primer then Halfords Gloss Black, then Halfords Gloss Lacquer , but still the finish was not good enough.
I tried T Cut, Glass Polish. Jewellers Rouge, Future and even toothpaste (I'd read that this could be used as a polish), nothing was giving me that real high, ex-showroom shine or deep mirror finish.
Then I tried Turtle Wax Safe Cut or scratch remover.
WOW - what a difference the gloss finish I obtained with this product was better than all the others and I pass this along to others who might be looking for this high gloss finish on one of their projects now or in the future.