Since day 1 people have been hopeful that carsharing could provide a helpful leg up for low-income households - to get to job interviews, day care, grocery shopping. Perhaps not surprisingly, to date there's little evidence that they're interested. For one thing, until now, carshares have concentrated on placing vehicles in neighborhoods with mostly median income to more affluent households. And, surveys continue to show that the vast majority of members have 4-year college degrees or better (certainly because they're the people who live in the neighborhoods that carsharing currently serves). Some people allege that the hours+miles rate structure is too complicated.
City Carshare has had a partnership with the Calworks program for several years. I-Go in Chicago is wrapping up a low-income pilot project and should have a report soon. Flexcar recently scored big with over $1 million in funding to subsidize rates for participants in job-training programs under the Jobs Access Reverse Commute (JARC) program in the current federal transportation funding.
Basically, all these programs are used to reduce rates and fees - typically half of what the company's going-rate is. In the case of City Carshare, the program reduces usage to $2 per hour + 22 cents per mile between 10 am and 10 pm (and further cut in half during overnight use). Application and membership fees are waived. Some of the funding is used to locate vehicles in neighborhoods that would not otherwise be attractive to the carsharing company.
One difficulty for a not-insignificant number of participants in job-training programs is that they may not have a good-enough driving record to qualify (one or two major violations in the past 7 years and you're not eligible). And, company requirements for a valid credit or debit card for billing may cause problems for others. Even with such limitations, these programs should provide a valuable benefit for those who are able to take advantage of it. The proof will be when formal evaluations are completed.
It's not often that carsharing gets compared to transit, but Wendell Cox, transit-basher extrordinaire, purports to show that subsidizing carsharing memberships (or leasing a car for the household in areas where carsharing is not available) is cheaper than providing paratransit services for low-income. Below is a link to the page showing his calculations. You'll have to read his FAQ to understand them (and somewhat mistaken assumptions about carsharing)!