Once you pick a specific car, provide the VIN to the insurer to set the start date for your planned purchase day.

Ask your agent for an insurance binder , which is a temporary document proving coverage before the official policy is issued. If You Don’t Have Insurance Yet

You can shop for quotes using just the make and model of the car you intend to buy.

Most major insurers allow you to purchase a policy on your phone while at the lot and receive digital proof within minutes. How To Get Proof of Insurance - Progressive