Baiting.
Clarkson, of course, after getting a few complaints of this type, has spent most recent series of Top Gear trying to put something in each show that'll have the hordes of Little England reaching for the phones.
I can't recall whether it was the series just gone or the one before, but I and a friend coined the game of Top Gear Complaint Bingo; trying to guess during an episode which items would be the complaint making the news during the following week. Sometimes we were spot on, sometimes way off; the Porsche pipes episode I vaguely recall Clarkson saying something ridiculously offensive and baiting during the news, but it was the shock-horror-smoking-ban-violated action that got the phones ringing.
My impression is the chap's endlessly amused that people who hate his show and everything he stands for waste an hour of their life every week watching it to find something to complain about.
Incidentally, have you looked at the BBC's public responses to complaints page? Almost a third of complaints seem to be based on a template of, "Interesting thing happened in Eastenders storyline. How dare they!"