it looks like my mirror cap came off. I’m not sure why. I must have hit something or somebody hit me. I was wondering if someone can suggest a reputable website to source the part to replace it. Thank you in advance
Toyota sells already-painted mirror backings but you're going to want to take that off and look inside there to ensure nothing else is broken...which would require buying both parts of the mirror, not cheap. I have a Toyota dealer in Denver who sells OEM parts around 20% less than MSRP so often use them...and picking it up saves on shipping costs. Search your local dealers and use your VIN to ensure you get what you need.
The corner probably just needs to be snapped back in place. But if you take it off and take a pic of the underside I can tell you if anything's broken. To take it off correctly, you pop the mirror glass off(be careful of the heater and blind spot monitor indicator wires), then use the tip of a flat-bladed screwdriver to release two prongs on the upper outside portion of the mirror housing. Then you pull it straight forward(towards the front of the car). It takes a little finagling, but the cover is pretty durable(which is why I think yours isn't actually broken). But if you just want to get the part, here you go: Side View Mirror Cover If you add stuff to your order to get to $75(I suggest wiper blade inserts, oil filters, and/or air filters), you'll get free shipping.
Toyota OEM mirror covers are only about $50 and they just snap on or off. It is a one-minute repair job that requires no tools. Simply pull off the old one and snap in the new one. Crazy fighting couple takes out mirror cover | PriusChat
Thank you everyone for the comments and particularly for the URL to Lewis Toyota Topeka part number. I got the part and I installed it today. Everything looks great
