The product that you are asking about looks like it might do the job. In the past I tried a bumper dye (can't remember the name), and after dabbing a little onto my bumper, I could see a disaster about to happen, so I quickly stopped. Up till now, I just coat a good silicon liquid (Black Jack), onto the black trim areas on my vehicle after washing, and have been satisfied with the result, however, it all turns to s**t the minute I go off-road, as the dust sticks to the silicon coating.
If you try this product, let's know what results you get. :rellye