How do I get insurance on a car I have not bought yet?

You can get quotes in advance using the year, make, model and trim, then finalize the policy once you have the VIN. Call your current insurer or shop new quotes, tell them the expected purchase date, and ask how quickly they can issue proof of insurance. Many insurers can add a vehicle the same day by phone or app. If the car is financed or leased, ask the lender what coverage and deductibles they require so your policy meets them.