The only reason that the argument that suburbanisation = republican voting got popular on the left was because they were frustrated at their inability to win over the voters. We made the same, sad excuses here: 'Essex Man is irredeemably Tory', 'The Affluent Worker' etc etc etc. They were just attempts to explain away the fact that the left was addressing social problems of thirty years earlier, unable to relate to the society that existed in the here and now.
Of course it is true that people are alienated, but their cars are just an expression of that, not a cause. And their cars are not the only expression of alienation, either. Preoccupations with pollution and the delinquent consumer habits of your neighbours is how the middle classes express their alienation; there are lots of ways to mark yourself out from the common herd - one of them is to move back into the cities, now turned into exclusive enclaves by rising house prices. Hatred of the Suburbs is the contemporary form of hatred of the masses, since that is where the masses are.