Is it against the law to hide your car from title loan company?

You will have to check with a local lawyer to be sure, since some states may have a law that says it is illegal, though I have never heard of one. You don't have to hide it, just keep it on private property and make sure the property owner does not give consent for anyone to come on the property and tow it away. The owner should call the police if someone trespasses on the property.