Quote: Don't gp that far into it, just tell them you were waiting for the new cards to arrive.
That works. As long as no one questions the ticket date being the same as the insurance card date.
But, if they do question it (and I doubt it will happen); Show proof of your insurance of your other car (which I imagine expires in some time) and some sort of proof of buying the new car (like a copy of a check), and you're done. As long as the date on the check is within the coverage dates of your other car and within 30 days of your ticket date.