He and staff tried to work around the obstruction, but when he got a delivery in the afternoon it proved problematic and he tried to contact the car owner by calling a phone number on the window.
Unable to speak to the defendant, the man contacted the Dunedin City Council and the car was ticketed.
A few hours later, when the driver returned and found the infringement notice, he confronted the business owner, who admitted he had called in parking wardens.
Giving evidence this afternoon, the complainant said the man told him he would get off the $40 ticket.
"I was a bit intimidated because he did it right in front of my face," he said.
The next day, the car was parked in the same spot prompting the businessman to text: "clever parking, dick head".
He then posted on Facebook a picture of the inside of the car which showed a child seat secured by motorcycle cables, with a disparaging comment.
A couple of months later the man said he started receiving photos of a partially-clothed woman from an unknown number.
Then he got another anonymous message asking if he fitted car seats or whether he would "nark me to the pigs".
He told the court he assumed it was the same man from the parking dispute because of the reference to child seats.
Mr McClenaghan said what followed was a varied campaign of harassment.
The complainant began getting numerous text messages and calls from gay men in early 2013.
When he spoke to one of them, he found his number had been left at a notorious homosexual meeting place.
The man went there and found three locations where his number had been written in black pen.
He painted over them and replaced them with the defendant's number, the Crown said.
In 2014, it is alleged the respected state employee set up a profile on a dating website featuring the man's photo and name.
The advert had the title "new gay male to play" and the person running the account encouraged people to contact the man.
There was also instances of the complainant's name being graffitied around town along with homosexual references.
His business was targeted as well, Mr McClenaghan said.
Twice it was hit with a "paint-ball grenade", he told the court, and adjoining business owners were told their neighbour was sex offender under investigation by police, via anonymous letter.
The Crown said the most "alarming and malicious" threats came on December 2, 2014 when the defendant allegedly told man to "buy something bullet proof" and to "get your affairs in order".
The trial before Judge Paul Kellar, without a jury, is scheduled to last a week.