Robert Raine, 25, followed the man into Tesco at Simonside, South Shields, after they were involved in an incident on a roundabout moments earlier.
In scenes captured on the victim’s mobile phone, furious Raine leaned out of the driver’s door and shouted abuse.
He then spat at the man’s car – and twice slammed his door against it as he remained in his seat, magistrates in South Tyneside heard.
Raine and a companion, who had stepped out to film his pal’s aggression before getting back inside, then sped off on Monday, May 4.
Prosecutor Ian Martin said: “It appears that there was an issue at a roundabout nearby where the defendant was aggrieved by the victim’s driving.
“The victim has pulled into the Tesco car park and the defendant has followed him in. There was an exchange.
“The incident was captured by the complainant on his mobile phone. You’ll note from the defendant’s record that there are a number of previous convictions.”
Mr Martin said repairs had been quoted at £803 which included £333 for a fresh paint job.
In a statement read to the court, Raine’s victim said he had been left fearful by the attack and scared to get back into his car for several days.
David Forrester, defending, said: “Mr Raine opened his car door and banged it twice against the other car door.
“What you see on the video is Mr Raine in an emotional state. He’s a young man who had quite significant mental health problems.
“I’m a little perplexed by the account of the complainant in this case. In the video you see him wind the window down.
“In his own account he indicates that he spat back after Mr Raine spat on his car. It wasn’t the reaction of a shrinking violet.”
Magistrates ordered Raine, of Egerton Street, Middlesbrough, who pleaded guilty to causing criminal damage, to pay the man £803.90 in compensation.
There were no court costs or victim surcharge.