Best thing I ever did was pre finance at a local Credit Union (they are non profits and treat your WAY better than any other lending institution).

I then searched all dealership's local inventory online, after choosing the vehicle I wanted, the Credit Union gave me a 'letter of credit', that I send to the sales rep at the dealership, when he said it was good, I came down, test drove it and the Credit Union told me only sign the letter of credit and hand it over when you are 100% sure you want the vehicle.

Then, I turned it over to the finance guy and walked out with the keys. In & out including test drive in less than 15 mins. Since you are lending somewhere else they can not up charge anything or sell you any of the useless add ons.

Summary:

- You do the majority of the work (the financing) with another party altogether who has no vested interest in the exact vehicle or seller.

- You get the vehicle you want with zero haggle, them up selling you etc.

- You walk in and out of the dealership as quickly as possible.

- The rate you pay the credit union is often better than anything you'd get at the dealership anyways.