I have seen a few Prius C here with a missing right side mirror, these poor cars are not respected because they look small.

Your mirror housing is fine after 3 smashes? and the mirror turn signal? I think you could get it from Amazon, here

https://www.amazon.com/-/es/Extafit-8210L-conductor-9-8-compatible/dp/B07GC9S2WN/ref=sr_1_4?__mk_es_US=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=Toyota+prius+c+side+mirror&qid=1630585968&sr=8-4#customerReviews

And here

https://www.amazon.com/s?k=Toyota+prius+c+side+mirror&__mk_es_US=%C3%85M%C3%85%C5%BD%C3%95%C3%91&ref=nb_sb_noss_2