I think its a common mistake to write off companies which have a physical aspect as "not software companies".
The company I work for delivers food to people, but we're very much a software company in that we couldn't possibly compete with the huge players in this market without smart software which lets us run it with the minimum of people. I'm fairly sure ZipCar are the same - there are many car hire organisations, but not that many which can get by without having to rent premises and huge numbers of people to look after car keys and signing in and out.
The company I work for delivers food to people, but we're very much a software company in that we couldn't possibly compete with the huge players in this market without smart software which lets us run it with the minimum of people. I'm fairly sure ZipCar are the same - there are many car hire organisations, but not that many which can get by without having to rent premises and huge numbers of people to look after car keys and signing in and out.