I've just had to take another look at my invoice in detail to figure out the exact deal I got. It seems I'm not paying as much as I thought.
It looks like the dealer has taken £4,966.67 off of the ex-VAT vehicle price of £17,366.67 bringing it down to £12,400 ex-VAT. So I would assume this is the £4,500 government grant plus £466.67 of their own money to get the deal through.
They're then charging £250 manufacturer's delivery charge bringing the sub-total to £12,650. Then they added the VAT on plus £55 first registration fee bringing the price to pay to £15,235.
However, the dealer also then contributed £798.90 to the finance deposit, which effectively brings the price down to £14,436.10.
I then paid a £500 deposit with £1,802 left to pay when I pick the car up. This leaves £12,134.10 being financed which he said would work out at about £165 per month (sorry, don't have the finance details on me).
So in total I'm paying:
£500 deposit + £1802 when I pick the car up + 48 monthly payments of £165 which works out at £10,222 before having to pay the balloon payment although I can't remember if he said this was £5,500 or £5,800 now. So assuming the latter it works out at about £16k all in for the 22kw Fortwo Prime Premium model.