I just recently detailed my car, and got a bit of wax on some black plastic trim on the underside of the rear bumper. This stuff will not come off - and it is completely ruining the look of the freshly detailed car! I have scrubbed it with water, car wash and water, goo-gone, and goof-off, and nothing has worked. Any recommendations on how to get this off so my trim piece looks good again? The trim piece is black plastic and has a grain to it, and the wax I used was Meguiars Gold Class liquid wax. Thanks in advance for the help!