Five different nonplanar mirrors were evaluated as driver-side rearview mirrors in a field test using Ford employees. Two were spherical convex (differing in radius of curvature), and three were aspheric (differing primarily in the proportion of their surfaces over which radius of curvature was variable). Each participant drove for four weeks with one of the nonplanar mirrors. At three times during the test the participants filled out questionnaires concerning their experience with the mirrors. Driver preferences for the experimental mirrors increased moderately between surveys at one week and at four weeks. At four weeks, all five nonplanar mirrors were preferred to the standard flat mirror by at least a small amount. For each of the five mirror designs there was a large range of opinion. Most notably, a small number of people strongly disliked the aspheric design that involved the largest variable-radius area. These results indicate that nonplanar mirrors are likely to be welcomed by a large number of U.S. drivers, but some designs seem more acceptable than others, and for almost any design there may be a small but significant number of drivers who strongly prefer planar mirrors. The sample in this study had a limited range of subject ages, a relatively small number of females, and may have been biased toward people who have generally positive attitudes toward new technologies. The results should therefore be considered preliminary.