Engine began smoking while driving without warning. Driver looked at gauges, saw that everything looked normal, then pulled over and exited vehicle. Shortly thereafter (within 15 minutes,) front end of vehicle burned and melted. Vehicle is currently in possession of insurance company for inspection. Car had overheated 2 years before this incident. New thermostat had been installed at that time. Car burned through oil regularly. Driver refilled when filling gas tank. Car was up to date on oil changes.