Quick question... before i bought my rx8 i was thinking about doing a preorder instead of just walking up to the dealership and buying whatever they had on the lot.

The problem though is I have to trade in my car at that time. So l'm wondering, could I have negotiated how much they will take my trade in for and do a preorder?

Your trade is worth what the dealer will pay for it on the day you trade it.

That said, I have ordered cars before and got the dealer to sign for a "pre-determined" price for the trade. Usually there is a stipulation by the dealer in the contract that the trade has to be in the same condition as when they appraised it and there is also a mileage restriction as to how many additional miles the car can have.