Here's a trick - after you wash your truck, grab some aluminum foil from the kitchen, tear off a small sheet, use the shiney side of the foil to polish the rim. Dunk the piece of foil into the wash water and just like your polishing your rims. After you've gone over your rim, rinse it off like normal and you will see a difference! I know it sounds bogus but it does work!
Never Dull is good stuff! we used to have a can of that stuff for our GP's polished rims, now we use Meguiars All Metal Polish -Mike-