The only descriptions of the people who arrived in the car are that one was a white man, aged between 19 and 22, who had a heavy build, black hair and a patchy beard.
The other description is of a white woman in her 50s with blond/ginger shoulder-length hair.
Det Sgt Neil Allison said: “From our investigations so far, we believe this to have been a targeted attack. However, the fact it took place on a Sunday afternoon in a very residential area is concerning.
“Officers have been carrying out local inquiries and checking CCTV, but we are keen to hear from anyone who may have seen what happened or has any information that may assist our investigation.”
Anyone with any information on the attack should contact the police, external.