Yeah ok, don't pay your property taxes and see what happens, don't pay your home loan and see what happens. You only think you own these things, you don't. You feel good about saying you do, but think about it, don't pay your property taxes and what happens?
As far as stealing, please!!!!!!!!! What is the difference between a person who takes clothes out of a store without paying for it and a person who does not pay their car loan?
I deal with deadbeats every day, most are just bums who are looking for any loophole or excuse not to pay for the goods or services rendered on their behalf.
And before you jump on me, don't for a minute think you are not paying for the acts of these people in many other ways.
As far as your statement of self defense is concerned, Texas is not like most places. In most places, not all, you can not defend property alone with deadly force.
If you think the creditor owns the vehicle until it is paid off, you will get a nasty surprise if you try to steal it (and that is the correct terminology) from someone who is not delinquent in their payments.
You will find yourself in jail for theft.
So much for your ownership.