If I could would you
If you tell your salesperson that you want to think it over, they will move to step 5, which is "If I Could, Would You" and goes something on the order of this: "If I could get my manager to make you the best offer, would you buy this car today?" This is the start of a commitment that will be used against you later. After they have run back and forth to a manager a few times, marking down the price and trying to get you to make some commitment, they will remind you that you said you would buy today, and this is the best deal that can be had. So tell them, that you will buy today if the deal is good enough! We will complete the sale. The final stage if your happy shake hands and move on!