I think you can control for socioeconomic class of the areas. Though I would argue that an area where black people are more likely to be unable to afford proper maintenance for their vehicles, are more likely to be poor in general, may be an area where other disadvantages (like the lower wealth per family and employment rate for African Americans, and were blacks got worse loan terms, or weren't allowed to rent or buy in better sections of town) may contribute to a systemic bias.