Now I have a shop and there is one very important point as far as I am concerned with this and that is they have not made the car available to you whilst still at the old price.
Look at it this way, say you ordered the car in November and it arrived mid january but you told them to hold it until March 1st to get on a new plate and than the price dropped while they were holding it for you then I don't think it would be fair to ask for a reduction.
However, you have ordered a product and by the time it has arrived there is a new price for that car, they have to, in my opinion, offer it to you for the new price as they have not managed to get it into stock for you whilst at the original price.
To be honest, this is one of the reasons I would never buy a new car, it is not just the fact that you loose 17.5% vat and 12% dealer margin straight away, but also by the time you come to sell it I bet half the options that you originally paid for are normally now freebies.
My mate bought a new A4 avant sport in Jan 04 I think it was, he paid £1400 for the body kit, £250 for black headlining, £1200 for leather and another £1200 for the 18" wheels, just a couple of months later the S-line arrived with body kit, 18" wheels and half leather for £1000 to say he was annoyed was an understatement, his car cost him £29k and the S-Line he could have got for around £24k with nearly the same spec.
He was even more gutted when he was offered £13k back on it last month, main reason being, most people prefer the S-Line! /ubbthreads/images/graemlins/frown.gif
To be fair I don't think the price you paid and the new price is that bad, you are hardy out at all really.