A sizeable number of crack cocaine users trade temporary use of their vehicles for small amounts of the drug. While the majority of these crack-for-car contracts are fulfilled without police intervention, many are not. These failed arrangements have the potential to cause a wide range of problems for police and the community. Using semi-structured interviews with police officers and active crack cocaine users, the authors examine how crack-for-car transactions come to law enforcement officers' attention and how police respond to and perceive the practice. Findings reveal that police believe that these incidents: artificially increase motor vehicle theft rates, waste police resources, perpetuate the drug market, and contribute to tenuous police-citizen relations. Findings have important implications for understanding police-citizen interactions and for developing effective policies. (Published Abstract)