How long do I have to register and insure a car after I buy it?

I just bought a 1997 eclipse GS from a private party and they left there plates on it, but I was just wondering how long I had before I needed to register the car under my name and insure it. Also how much trouble can I get in driving the car for the first week if I got pulled over since I need a week before I could afford registration.

Create a video blog