We've been sharing a car with a housemate for one year now. This has worked really well. It's convenient being about to drive places, we can leave the car seats in (though we keep a backup set in case we need to go somewhere when the car is out), and it's less thinking about transportation. Neither we nor our housemate use the car that often, so it's rare that we both want to use it at the same time. We do have pretty different usage patterns, however:

We have a larger number of shorter trips, while our housemate has fewer longer trips:

Our biggest category by far is driving to the next town over to visit my dad (and other family), 6mi round trip. Most weeks we drive over on Tuesday for family dinner, and then many weeks another time as well. Before we had a car we would typically take the bus over, and then either take the bus back or my dad would give us a ride. With covid these weren't options (we weren't being inside with people we didn't already live with), and would instead bike there and back with a trailer. Driving is much faster than either of these, and a lot more convenient.

In figuring out whether it made sense for us to get a car, Julia and I had made some ballpark guesses about our usage:

This was 137 trips (96% actual), totaling 4,180 miles (186% actual). The biggest delta here is dance gigs: in April 2021 I'd expected that vaccination rolling out meant dances would resume, but then there was Delta, seasonality, and Omicron. I think I drove to two gigs (Worcester twice, with Kingfisher in November and Gianna and Rebecca in March). With that corrected the guesses would become 124 trips (87% actual) and 1,480mi (66% actual). Looks like we're using the car in more situations than we'd expected, by a factor of ~25%?

There was one day when we tried to use the car but couldn't: the battery died, probably just from age. Aside from that, no other reliability issues. Maintenance expenses have been pretty low: a total of $319, most of which was an oil change and the replacement battery. At the same visit we also had both the front and rear axles replaced as part of a recall, fully under warranty. We didn't itemize gas, but it's an efficient car (~32mpg) and based on the total mileage and average cost of gas our portion was probably ~$200. Our half of insurance was $515. This comes to about $0.39/mi, plus depreciation (which for this very strange year was negative). I do expect higher expenses in future years: the car is ten years old, and there are a lot of things that can wear out.

Overall, this has been great and I'm happy to continue with it!