My wife got in a fender bender earlier this year that required the front bumper and right fender to be replaced. The shop used an aftermarket bumper cover and I can easily tell where it doesn't quite match. I showed my cousin who does body work and he said that's normal for an aftermarket bumper, but most people don't notice it. If it ever needs replaced again, I'll get a used one instead.
Yeah there pretty flimsy. There's no structural really behind the bumper designed to hold the plastic bumper out and firm just the impact shock aborber rail so the aftermarkets being so flimsy are pretty noticeable. They look bad. Most body shops won't paint them as they don't want to hear the complaints. The oem is twice as thick. And thats why a new bumper costs $1000. I see used one's on eBay all the time for $100-150. Here's one I'd jump on with an offer: 04 05 06 07 08 Toyota Prius Rear Bumper Cover Used 2004 2009 | eBay