I fed mine down the side of the car under the plastic trim then to get in to the boot I slid the cables down the side of the seat where the back folds down, you could see them and it work really well.
2.0l 6th gen isnt the best for economy, I used to get from a full tank 330 before the light came on, It needed a 6th gear tbh. When I did only town driving and short journeys my mpg would plummet. I think its the nature of this car.
Adams right, the symbol on the dash is important to help, also not starting first time might give some clues too. Are you with the AA they can come out and check the fault and tell you on the spot whats up.
Have you driven a petrol Honda? They are great engine, can be very frugal but can privide lotsof drama when you need some beans, vtec is a cleaver system, if you get chance try the 2.4 out, Brett managed 50 mpg out of on a test. Just a thought.
Paul you are a hero to these filthy cars, well done, I'm moving to Scotland soon .........,you know I might give you a call in the spring for a top notch job ;)
I would start by reading honest johns website and parks guide review to fully understand what the car is like. Regarding the model you can get all the difference explained on Parker guide and the Honda website as the still sell this car from new.
The diesel boys will answer all your questions...