He had stopped selling bigger cars such as Holden Commodores because buyers sought "a bit more economy".
However, he still sold larger vehicles such as Nissan Skylines and Muranos to families.
Mr Cooper noted buyers were more positive about their budget and spending more now than two years ago.
Many of the vehicles he sold were from 2005 or 2006.
Tony Hammond Motors manager Tony Hammond also said the Nissan Tiida was the most popular car he sold last year. He said they would import six of the vehicles every month from Japan and would sell the six as soon as they arrived.
"For a decent sized car, they are as good as you can get."
Mr Hammond said more people were moving away from bigger six-cylinder vehicles.
"People are leaning more towards saving money on fuel and maintenance.
Turners Car Auction branch manager Karl Jarmine said the bigger commercial vehicles were still popular.
"We sell 400 cars a month, so we have a pretty good idea, all four wheel drives are hugely popular."
He said the versatility, engine size and the tray on the back of cars like the Hilux and Rangers meant the "best of both worlds" for his customers.
According to MTA figures for new commercial vehicles, the Ford Ranger was the top seller in Tauranga, followed by the Toyota Hilux and the Holden Colorado.
Motorcycle sales rose, at 356, up 24 per cent on 2012.
The top-selling cars nationwide between 2009 and 2013 were predominantly efficient four-cylinder models.
The Toyota Corolla continued to dominate the new and used market, but traditional favourites - such as the Subaru Legacy and Holden Commodore, the only car with more than four cylinders in the top 10 - had slipped in popularity.
MTA spokesman Ian Stronach said the price of 91 octane petrol in 2009 was $1.63 a litre but by the end of 2013 it was close to $2.20 a litre.
"With petrol costs increasing around 35 per cent in that time, it was entirely predictable that there would be a swing to smaller-engined cars." Additional reporting Matthew Backhouse