If you wait too much longer you will not be able to find any 07's, especially if you are wanting a specific color with specific options. I would rec. getting an 08 as you will get an extra year of less depreciation, bigger brakes, much more refined and nicer interior and seats, and the rebate is only 1,500 difference. You will make more than that up on resale.
But if you are dead-set on an 07, I would personally go do it now.
But if you are dead-set on an 07, I would personally go do it now.