Why do you feel obligated to continue to talk to a rude debt collector while you are driving and let him upset you all the way home?  You are being just as rude as the caller because you are a hazard to everyone else on the road when you do that.  Either don't answer at all or turn the phone off before you run into and kill someone.  You don't need to make up any excuse to do that and to do otherwise is, quite frankly, irresponsible.

See:
http://www.distraction.gov/

This man, Mike Hunter, was the most rudest, most threatening person I have ever encountered. He is a debt collector, and, as a debt collector he threatened me and talked to me in a very harassing voice. I told him I was driving and could not talk to him and he threatened me even more. As I got home, I was in tears and he still wouldn't stop harassing me. I finally had to hang up on him. When he called back, my husband answered the phone and gave him back some of what he gave me. Funny how it is that he eventually hung up on my husband..>>WHAT A CREEP and an unprofessional jerk.

please stop call

a location service