Buying a new vehicle right now

Probably looking to buy at THE worst time with these tariffs looming. I've met with two dealers and have a meeting with a third set for next Saturday the 8th. The dealer I just met with today seems to have a pretty fair deal in place for a new build for me. Do I just say nuts to the other guy and sign on the dotted line before Feb 4th or will it take some time for the effects to take place after the 4th?