I see the occasional Prius C used for rideshare here in Chicago. I once owned a Yaris which is similarly sized. 99% of the time the size of the Prius C is not going to be an issue.The only potential issue is an airport dropoff/pick up with 3+ passengers with suitcases which occurs rarely but is a possibility. With 3-4 passengers there is not much room in the back of a Prius C for luggage. So far I've had only had one run to the airport with 4 college students going home for the holidays. Luckily (for them) only 2 had large suitcases and the others had backpacks and they were able to all squeeze into my Prius. I wouldn't purchase a Prius C to use with Uber/Lyft but would use it if I already owned one.
Those companies have standards, don't they ? Ask them. If nothing else, it will limit the range of clients that you can serve.
I do uber and Lyft and haven't had any issues. Yes it's a small car but most people just compliment how nice the car is (I drive a 2016 4). Posted via the PriusChat mobile app.
We use one to Uber. The only time that there was an issue was when two basketball players wanted a ride and at 6' plus tall, both front seats were as far forward as possible.