you can wait. but that doesn't protect you from price increases that may happen. the ESP from flood ford warranty does start the coverage from date of vehicle purchase. not from the extended warranty purchase. regardless when you get it. I am sure you're aware of that. From what I read there are some items that are in the grey area of coverage with the 3yr 36 B to B warranty but if you have the premium it covers it. I have no clue how true that is but I just got it after about 4k miles, I didnt want any issues. I got my prorated refund of my 18's premium warranty back and didn't feel like waiting til 36k miles