Most trips in U.S. metropolitan regions are driven alone, which is costly to individuals and society and leads to congestion and air pollution. A more efficient, but less convenient system would allow drivers to share cars. A shared-use system aims to reduce traffic by reducing the number of cars needed by households and encouraging commuters to walk, bike, and use transit, at least for part of their trips. For commuters especially, shared-use vehicles could offer a low-cost, low-hassle alternative to private vehicles. Furthermore, carsharing could help air quality by incorporating low-emission vehicles into shared-use fleets. The CarLink field test combined short-term rental vehicles with communication and reservation technologies to facilitate shared-vehicle access. The ten-month demonstration was implemented and researched by two teams at the Institute of Transportation Studies at UC Davis. Project partners included American Honda Motor Company, the Bay Area Rapid Transit (BART) District, Caltrans, PATH, and Lawrence Livermore National Laboratory (LLNL). INVERS and Teletrac provided advanced carsharing and vehicle tracking technologies. Using surveys and focus groups, researchers explored attitudes toward the carsharing concept over time. This study builds upon the work of the CarLink longitudinal survey by linking carsharing market potential data to the CarLink field test population. Although the CarLink participant sample was not statistically significant, valuable lessons may still be drawn from the results. The CarLink field test results include: operational understanding, participant profiles, behavioral findings, economic viability, and directions for future research. Operational and participant profile highlights are also discussed here.