The company says the maximum hourly charge to repair a car has increased from an average of £52.96 in 1998 to £76.37 this year, while independent garages charge between £28 and £41 an hour.
On a marque-by-marque basis, Warranty Direct found that over the same period, VW technicians' labour rates have almost doubled from £51.11 to £100; BMW up by 85.6 per cent; Volvo by 79.2 per cent, Land Rover 77 per cent and Alfa Romeo 66 per cent.
The most expensive dealer recorded by Warranty Direct in 2003 was a BMW franchise - charging an hourly labour rate of £115.62 including VAT.
At the other end of the scale, the Mazda hourly rate has increased by just 2 per cent, with similar minor increases recorded by Citroen (up 3.3 per cent ) and Renault (up 3.6 per cent).
“Customers are having to pay more and more for the salubrious surroundings of a franchised operation. Admittedly, a shortage of skilled technicians, with many moving into the independent sector, is forcing rates of pay upwards too,” said Warranty Direct spokesman Duncan McClure-Fisher. “It's also a bit ironic that as new car prices have tumbled, squeezing dealer profit margins on the way, labour rates have rocketed.”