If thats the case and your paying around the same monthly price then looks like I should be paying alot less a month than what they quoted, with half the extras
To work out if there is any equity left you'll need to find out the predicted value. i'd guess that the dealer will have left between £500 and £1000 of value.
Under a PCP type deal the deposit can be best thought of as an initial payment not as a returnable deposit. This can either be allocated to reducing the monthly payments making the "deal" more affordable per month which is the most common method of structuring a deal or to reducing the balloon making the deal more expensive per month but leaving a larger amount of equity.