Hello, and thank you in advance for any advice!

I currently own a black on black 2007 Mazda Speed6 GT. It has very dark tints, Aftermarket Intake and exhaust, It has about 5 small dings/indents from shopping carts. On the hood it has 3 chips on the paint from pebbles that show rust (one shown in picture) and two other problems with the front fender which are also shown in the link below. http://imgur.com/a/TGp0J

However! It only has 46,700 miles on it and the interior is in perfect condition. I also have read the car is rarely traded in and doesn't usually spend much time on the lot (correct me if I'm wrong)

I am buying the 2014 Mazda3 iGT. I don't want any of the options and i want it in meteor grey.

I plan on paying the full amount in cash for the new Mazda.

My questions are as follows 1) how much do you think my trade in is worth if you had to venture an educated guess?

2) when should i introduce the fact that I'm going to trade it in? Is it after we have decided on a price?

3) there is currently three incentives i qualify for from the main Mazda website - The college graduate incentive, Loyalty incentive, and one for buying a mazda 3 which totals $1,700 dollars. When do i bring this up during the negotiations? Is it after we have decided on a price?

4)How should i approach this, do i go from dealer to dealer and see who will give me the best dealer? Do i call around and ask for a quote over the phone?

Any help, or extra advice you have would be great and thank you in advanced. I'm really lost and I'm getting married soon so any money i could save would be great!