I don't go to London often so I'm not really sure. I drive, but I certainly wouldn't drive in a city like London. Hell, I wouldn't even drive into Ipswich back when I lived in Suffolk, and that's not even officially a city. The London underground goes everywhere and the trains go every 3 minutes so I don't see any reason not to just use that, and then there's the buses too. I'm sure many people do drive in London though, otherwise they wouldn't have introduced the congestion charge there...
(York is an exception to my "don't drive in cities" rule because there are only like... three roads that I ever need to use)