Properly filed judgment liens in Texas attach to any non-exempt real property you own. If you make the property in question your homestead, nothing will happen to it. The car is a different matter, as it is personal property and not real property. However, Texas also allows exemptions for certain personal property, including one car.
Nonetheless, you should probably try to settle this debt and get the matter resolved, in my opinion. Judgments can be enforced against your non-exempt property, bank accounts, etc. Proceed with caution and seek counsel.
I am an attorney licensed to practice in the state and federal courts of Texas only. Any advice provided herein is offered for educational purposes only. No attorney-client relationship is created through the use of this forum, and cannot be created through asking and answering questions here. You are strongly encouraged to hire a lawyer.