Just a warning that although the Civic Hybrid is exempt from congestion charging it is not automatic! The car has to be registered with Transport For London and it costs £10 a year.
If it is not registered and you drive in to London and dont pay the £8 congestion charge you will be hit with a £50 fine.
The form to register you car can be found at:
http://www.cclondon.com/downloads/Drivers.pdf
Nickp.