Buying a used vehicle, financing from private seller.

[bizusn]

Texas- I'm buying a truck from a private seller in Texas. I also live in Texas. The contract that he proposed has all the normal mumbo jumbo in it, but I have one concern. In the contract, it doesn't explicitly state that he cannot repossess the vehicle unless one of the conditions is met. Is it possible that he could just want the truck back and repossess it? Or should I change the contract to state that the seller can not under any circumstance repossessed vehicle unless one of the conditions above is met? Thank you for your help!