I've used a bunch of the interior paints... SEM, Duplicolor, and Plastikote. I've found that the plastikote is a 100% perfect color match to the original GM interior in my Camaro, so I've used that the most. I did some kick panels with it, and they've stood up to every bit of abuse I've dished out at them. They've been installed and removed dozens of times, kicked, etc. The key is proper prep. Sand the plastic lightly, clean the product with a plastic prep (I used the SEM stuff) or mineral spiriits, then do a few light coats.
Overall, my complaint with the Duplicolor and Plastikote stuff is that they can be a bit too glossy, and due to the cheaper nozzles, you don't get good enough atomization to spray light coats evenly. If you don't lay it on a bit heavy, it doesn't lay down flat. The SEM seemed much better at atomizing and allowing me to get complete, smooth coverage with less paint, which meant the natural texture of the plastic was better preserved.
Here's the first pic. Here, the housing that the monitor is in was painted with SEM, wetsanded, and hand rubbed to provide a perfect match in luster and color to the original (unpainted) plastic housing that the radio & heater controls are in. Pay no attention to the dash board... it was white from dust/dirt:
Here's another pic, this time of my old set of kick panels. The kicks were painted with the Duplicolor Charcoal paint. My door sills are the original, unpainted GM plastic:
