For what its worth here are my ramblings:
I thought the Jazz comes from Swindon, what's this about a boat?.
You can always haggle but if the deal makes no sense to the Honda dealer they will not do it, after all they are a business and not someone excited about a new car. There is no reason for them to give you a discount unless not doing so will cause their business to suffer, but they might offer things of value to you that are of low cost to them, like servicing. Borrowing money is currently cheap so there are lots of customers out there whose hearts may overrule their heads and the dealers know how to take advantage of this. Sometimes the showroom car has an unpopular spec, poor colour or missing options, and if you are happy with it the dealer may be pleased to get rid of that car quickly to you.
So long as you are an eager willing buyer you will pay more than a reluctant buyer who has other options including sticking with their old car or buying another make. So before seeing the Honda dealer get some other make quotes so the dealer knows you can walk away and spend your money with Ford etc. Do your homework, get quotes from the online suppliers like drivethedeal and carwow.
Remember that a new model will result in extra showroom footfall and more opportunity to make sales, so typically the dealers are less likely to offer discounts on new models. You may do better to wait until another maker releases a new model and Honda sales take a temporary hit as buyers visit other dealers, that would be a good time to visit the Honda dealer, at the end of a month when sales targets are under scrutiny.
Remember too that many sales will result in an old Jazz taken in p/ex sitting on the forecourt and doing nothing to keep the dealer in business until a wise buyer comes along and buys your perfectly good three year old car for a fraction of what you paid for it just to help the dealers cashflow.
So ask yourself exactly why you need to change your old car and what your budget is, then if you still want a new car do the homework, try and sell privately and be a cash buyer, get quotes from dealers in tough sales areas as a long train journey to collect your new car may still save you hundreds compared to picking it up locally.
Good luck, sorry I don't mean good luck I mean good planning as you think through how to get maximum value for your hard-earned cash.
