The driver was approached by a man in a balaclava with a knife as he sat in his vehicle in a lay by just off the M3 on Wednesday.
The suspect took his car keys and demanded that he transfer £3,000 into his bank account at around 8.45 that night.
He’s described as around 5’11” tall, of medium build and wearing a balaclava, a black hoodie and black jogging bottoms.
Any witnesses or anyone with dashcam footage in the area at that time is urged to contact police on 101.