That is it really, the film is more of less just a sequence of quite amusing and often fairly erotic adventures for Joe. Some of the adventures are ridiculous but genuinely funny, such as when Joe has to take a nun on a fare but he hasn't got any clothes on... after his previous adventure with a married woman (of course).
It is all a load of low-rent and predictable nonsense, with 70s stereotypes and misogyny galore. The nostalgia of 1970s London and all it's associated grime and sleaze makes the film highly enjoyable and very watchable, as does appearances from the likes of Robert Lindsay, Ian Lavender and Stephen Lewis. It is crap but a particular kind of British crap, so I loved it.
