http://www.mazdausa.com/MusaWeb/disp...entives.action
Put in your zip and find the real financing deal in your area.
Mazda3's can easily be had for under invoice. The amount below invoice you got is a good target price, but you can get the same elsewhere (as you figured out)
I'd still go with a leftover 2006 Mazda6 if I were you....