Even if you don’t get it in writing you can ALWAYS contest and demand proof from whoever the liquidator sold to - I personally would consider it pretty unethical to try to get out of a valid debt that you intentionally took on but it’s a tactic that is known to work and screw the usurers anyway.
You don't necessarily always need a title, just write a Bill of Sale to the buyer. This is fairly common particularly with older cars or cars that have been converted to racecars (but still quite street-legal).
Often the paperwork has been misplaced or lost.