12374668 - RH MOLDING KIT, RR S/D CTR (PAINT TO MATCH) - List $174.93
25635624 - RH MOLDING, RR S/D UPR (BRIGHT) - List $94.48
Top is the big panel, bottom is the seperate chrome piece on top (if your's has the option, looks like it, could be a glare from the sun)
Just referred to as a Rear Side Door molding