A car was found abandoned and on fire by emergency crews called to a Markyate street on Saturday night.
Firefighters from the nearby High Street fire station raced out to Buckwood Road to put out the flames in the silver Saab’s boot.
Herts Fire & Rescue Service spokesman Andrew Dawson said it looks like the blaze was started deliberately, but that it was only small by the time crews arrived.
They were called just after 9.25pm, and had put the fire out by 9.50pm.
Police spokesman Sarah Spence said the blaze had not yet been classed as arson, but an investigation is continuing.