JCT600 also beat the industry average of new car sales, seeing its figures rise by 10% in comparison with a 6% rise across the rest of the market.
The group has invested in improving customer service by increasing its staff numbers to 2,300, alongside a £18.3m acquisition of two Mercedes Benz dealerships in Harrogate and York.
Founded in 1946 by current chairman Jack Tordoff, the business has grown from a single garage on Sticker Lane, Bradford, into a regional wide dealership
Chief executive John Tordoff said: “It has been another year of strong growth as we have continued with our focus of striving to be the best car retailer rather than the biggest.
“While the market is extremely competitive, we have proved able to continue to win market share based on our 70 year heritage of offering great value, a choice of quality brands and outstanding service.
We are constantly looking for ways of improving the customer’s experience with ongoing investments in our team and dealerships as well as implementing industry leading initiatives.”