I work for a nissan dealer, And I'm the asst. Used car manager, They MUST disclose FRAME damage only, If you go to an honest dealer they will run a carfax report, and they will generally tell you that it was involved in an accident. If the vehicle has frame damage (wich I'm almost positive that it has) and they didn't disclose it, you can sue them or have them buy the car back from you.... Have the car inspected by another shop (prefferably ford) And if they find frame damage ask them to notate it in the recipt and take it to the dealer for proof.
Can you post pictures of the car and maybe I can tell you if it has frame ?? (the old polaroids)
 post the vin and I'll run a carfax for you............
and post it on this page.....
AEM Cam Gears, AEM CAI, SCT SF3 (Canned tune) and an exhaust = 114 WHP / 117 WTQ