Sarah Jane Smith drove a yellow 2CV early in her association with the Third Doctor and UNIT. She usually covered it when parked to protect it from the rain.
When Sarah helped Kal escape from UNIT HQ, she took him to her car and drove to the site of the Grid's disassembly before heading to RAF Weatherton. She later gave her car keys to Jenny Nettles so that she should leave the airbase before the Grid used the implosion missiles to destroy the area. Sarah followed the convoy moving the Doctor from Weatherton in her car and, after exiting it to help the Doctor and Hurley, Sokolov's men destroyed it with a melt gun.
Before Jenny left Earth with Kal, she gave Sarah the keys to her own car. (AUDIO: Kaleidoscope)