The car dealership group has a network of 160 sales and after sales outlets across the UK.
Revenue for the half year was up 3.9 per cent from £1.92 billion a year earlier to £1.99bn.
Adjusted pre-tax profit fell from £51.8 million to £28.2m.
Chief executive Robert Forrester said: "The first half has seen a strong trading performance with vehicle margin strength offsetting market driven volume shortfalls. The group continues to benefit from its focus on operational excellence around cost, conversion and customer experience aided by continued digitalisation initiatives. Cashflow generation has been strong and the dividend for the first half has increased again.
"The business is strategically very well placed with significant firepower to expand its footprint of franchised dealerships across the UK."
The board now anticipates that full year profits will be ahead of market expectations with a strong performance delivered in the key month of September despite ongoing supply constraints.