Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Works like a charm

My car is ten years old and a certain piece of semi-gloss black plastic trim has gotten some ugly white blotches from age and car wax. I put on Forever Black. Spent the whole night in the garage. Put on probably ten coats. Next day I started driving the car as usual. It's been probably 1-1/2 or 2 months. Been through a couple rainstorms. Black as ever. It is indeed a dye and not a paint, as you can still see the texture of the plastic. This stuff is good.