 According to an interview on the DVD, Michael Madsen (I) (qv) says  that Kirk Baltz (qv) asked to ride in his trunk to experience what  it was really like. Michael Madsen agreed, but decided as he went  along that this was time for his own character development. So he  apparently drove down a long alley with potholes, and then through a  Taco Bell drive through before taking Baltz back to the parking lot  and letting him out.