Matching texture is an art form. There are several different ways. Depends on the plastic you need to match. I have done things like spray a heavy coat of paint and lay a piece of vinyl on it to get the texture. Also have used old school crackle paint to get texture. My favorite product is texture paint from SEM. You can get it in a spray can...I shoot it from a gun. If you use this product you can vary the distance between the piece and the product...this will change the texture, amount of coats will change the texture, and you can lightly sand it after coated to change the texture. Best bet it is to experiment. Also if you have two pieces of plastic that touch each other is best to recoat both so they match.