No agent ? Too good to be true

I have two issues going against me for auto insurance. First is I bought a 23 Kia Seltos. The other is adding my 20 yr old son to the policy he's had three accidents, two very minor and the third he was hit by an uninsured drunk driver who was found at fault for the accident and got a DUI at the scene. Understandably, I talked to a few agents who didn't want to insure us. I currently have State farm for my other vehicle and they quoted me a very high quote, also understandable. I found a quote online from progressive for half the amount. Literally half, it says it includes liability , collision, and comprehensive . It seems to good to be true. Could I be missing something ? Has anyone not had an agent ? How much of a difference does it make ?