The incident took place on the 16th of February but Met officers say they were only informed about it on the 2nd of April.
A 79-year-old man was driving along Staines Road at around 4pm when his vehicle was blocked by another younger man.
An argument broke out between the pair and the older man has been left with life changing injuries.
Police say they have exhausted all enquiries but have been unable to trace the two women.
They also believe the suspect was driving a light blue var at the time of the attack.
Detective Constable Rory Atkins from West Area Command Unit said: “We have exhausted all relevant enquiries and we are yet to identify a suspect. We have been made aware that two elderly women witnessed the attack, the two women also came to the aid of the victim after he had been assaulted.
“We are keen to hear from these two women and hope that speaking to you will help us find the person responsible.
“We believe the suspect was driving a light blue car at the time of the attack. If you were in Staines Road around the time of the assault and have any information then please come forward to police stating CAD5587/02APR24.”