Some advice as to price increases on delayed delivery cars -
1. When ordering any new car, you should be given a new car order form setting out the price with options and the delivery date. I know no-one except sad lawyers like me reads the terms on the back, but they are entitled to delay without recompense, AND to give you notice of any price increase, and to charge it to you. Your only option is to say you no longer want the car.
SO -
Your best (if not only) opportunity to bargain is just before you sign. It's the only time the salesman/dealership is at your mercy.
Not so easy if you have a PX, admittedly, but here's (IMHO) the way to go if it's a straight purchase -
Tell the salesman you must have delivery on the due date, because you need the new car for business, or they are to provide you with a car during the delay, AND ask for a fixed price.
Point out the potential triple whammy of no car, no work and a price hike. It's really hard for them to defend. If his answer is no, tell him you'll speak to his sales manager and if necessary go somewhere else.
If you can get him to agree, get him to sign a piece of paper to that effect (to prove you have varied the conditions on the back of the form). Worked wonders for me, as my C32 was delayed from Oct 01 to Jan 02 - rather than a car (which I didn't really want) I took a discount off the contract price.