Back in the days when cars had chrome bumpers with plastic rub strips, I used ArmorAll to eliminate the old wax residue. Even after the ArmorAll had washed off the wax was gone.

If that doesn't work, use SoftScrub with a soft brissle brush.....(It won't hurt the moldings....I had a 2000 Chrysler Voyager with the same type moldings and I used it to get scuff marks out)

Then get DURAGLOSS 271 and do all the moldings with it (the bottle says that its for rubber bumper and flat black but it works on other colors...mine were dark green). Put it on in 2-3 light coats.....than let it dry about an hour.....then buff with a cotton towel......this will last a couple of months....it gives the moldings a satin like finish and hides minor imperfections. I used to do the Chryslers about 3 times a year.

Just make sure that the moldings are clean and free from all residue and dirt....if not, it will show where all the grime and dirt is embeded. To clean the moldings and bumpers I found that Simple Green worked well on road grime.

http://www.weathers.com/Duragloss/dura.htm