When did I say you should send him ANYTHING?

In EVERY state, there are provisions for purchase of a car. This is easy. But I disagree with others telling you to talk to YOUR state - you should talk to MO and see what THEY want. Once they issue you a temp tag/title, your state WILL honor it. PERIOD.

In my last case:
In Arizona, I bought the car with cash in the form of a cashier's check. We went to the bank and then DMV together. The DMV charged me $15 for a 30 day "temp title" that was taped to the back window, this authorized me to drive home to Georgia. Since the car was paid for, I had documents showing I had an Arizona title coming in a few days. Already had insurance, just stopped by my agent's office and gave them the VIN and a check for six months' coverage. As others have said, you need not do this, you can insure the car later but I dislike doing that.)

Funny thing: I did not pay sales tax in Arizona cause I was not an Arizona resident and was removing the car from the state, so they said I owed no tax.

Got home, applied for the Georgia title and that was that.

Funny thing: Did not pay sales tax there cause I bought the car in a different state and the lady said that I was "moving a car into the state" and when I bought it was not relevant cause I bought it out of state.

Make some phone calls, get insurance on it before you travel, check to see what MO wants from you to issue a temp title/tag and go up and get it. Generally, to tag/title it requires the seller provide a clear title signed over to you and you must prove who you are and pay the temp fee. Some states do make it more complicated than that, but Arizona was easy. When I bought the SE in FLorida, she just let me drive home on her plate - but even then, I got insurance on the car before I left home - thats just how I do things, I want a piece of paper showing I am covered.