It had a staff of 15 when Mr Greaney bought it in 1979 from founder Andy Dyke after both Mr Dyke's sons died.
"When I started it was all about how did your work as a panel beater," he said.
"We couldn't buy parts for most of the cars so we repaired them, so you had to have a good name as a repairer to succeed."
A good repair was still important today but business success was about service levels and turnover, he said.
"It used to be a medium crash would take 12 week to repair. Today these guys do the same job in three weeks."
He said the industry was now split between panel beaters with new equipment, needed to fulfil manufacturer's repair levels, and old-school panel beaters.
Last year City Collision Repairs proved it was firmly in the new camp, winning the prestigious national award for best panel beating shop from the Collision Repair Association. Previous awards include Best Presented Business 2013 and Best Shop Upgrade 2011.
CCR business started in Napier's Hastings St in 1916 before moving to Hyderabad Rd and then Onekawa in the early 1980s, across the road from its current site.
Six years ago it moved into its current purpose-built building which he said was a game changer. Previously cars were moved up to 20 times over course of a major repair, today a car is rarely moved more than five times. The industry norm is each move takes seven minutes.
His son Chris is manager, having started at age 18.
He said he always wanted to be a panel beater.
"It's what Dad did and I like cars," Chris Greaney said.
"After I finished seventh form I said I wanted a job.
"He said, 'No - you can do better things'.
"I said, 'I either had an apprenticeship with you or somebody else', so he took me on."
Chris Greaney didn't disappoint, winning the Golden Hammer Award for New Zealand Apprentice Of The Year in 2004 while also winning the NZQA Award for Highest Exam Results in New Zealand across all trades.
CCR now has 12 staff but productivity has increased markedly.
"We would do about 20 cars a month in the 80s because we got more money to fix them and there weren't many parts around," Chris Greaney said.
"Now we are now doing 25 a week minimum.
"The average cost of repair has reduced dramatically, because parts are cheaper, the cars are easier to fix and accidents are smaller because of the technology in vehicles.
"So we have to produce five times more than the 1980s and so this current site was designed to be more efficient."
Roger Greaney said the biggest change he had seen was computerised chassis-straightening machines, of which they have four.
'What used to take as days to do using a tape measure and a trammel bar, these guys can literally do in hours."
It continues to evolve, with a recent move to more expensive waterborne paint," Chris Greaney said.
"It is good for the guys, good for the environment and it is more efficient - it dries quicker so turnaround is much faster."
The business also has a computerised spot welder capable of diagnosing the type of metal, its thickness and voltage required for a weld to manufacturers' specifications.
Roger Greaney now spends most of his time in the workshop restoring cars and passing on skills, some from the wheelwright days.
He said giving back to the community is important. They sponsor local sports teams and racing drivers, but the business itself has been a pillar of the community.
While companies go through boom and bust cycles, each with a headline, it is businesses with stability that enable the wider community to prosper.
"We must have graduated a qualified apprentice for each of our 100 years," Roger Greaney said.
Last night CCR had dinner with more than 120 guests at Mission Estate Winery, on the exact date the Napier business opened its bank account 100 years ago.
