In general, when something you buy goes wrong (within the period covered by consumer legislation), you have no right to demand a cash refund or a replacement product. The vendor has to put the fault right but he can choose whether to do so by repairing the faulty item or by providing a replacement.
However, there's one important exception to the general rule. If a product is found to be faulty before you've legally 'accepted' it, you retain the right to a full cash refund. (You could, of course, choose to accept a replacement but this would be entirely at your discretion). Since your question indicates that there has never been a time, since purchase, when the vehicle was 'perfect', there is a strong case for arguing that you've never 'accepted' the vehicle. In which case, you're entitled to your money back (or, if you so wish, a replacement vehicle).
Unless you signed a contract stating that you were purchasing the vehicle directly from Ford (with the dealer acting as your agent), it is the dealer (and not Ford) who is responsible for putting matters right. (It would then be up to the dealer to seek compensation from Ford). So don't waste time arguing with Ford; pursue the dealer for some positive action.
Your local Trading Standards department might be able to give you further advice. (If you live outside of a unitary authority, they'll be part of your county council, not the district council). Otherwise, try your local CAB or look for a solicitor who offers a free initial consultation.
Don't let the dealer fob you off with statements like "We''ll have to get Ford to take a look at it". It's the dealer's duty to put matters right and (if you've not legally 'accepted' the vehicle) that means that, if you want it, you're entitled to a full refund.
Chris