30 seconds work plus paying to open the place, and the receptionist, and get mechanics off other jobs, and other overheads.
Mechanics don't make a lot of money, and garages aren't rolling around with their pots of gold.
If you're going to a car dealer rather than an independent garage you also need to consider the rest of their business plan. They have to pay for all the sales staff too, and the space for a show room, and there's not a lot of profit in selling cars. So that money also needs to be made by the workshops.
Even though they charge more per hour than a barrister...
A survey reveals that motorists are frequently paying more than £100 an hour for labour at car dealers franchised by manufacturers.
Hourly rates vary across the country, from £49 for Vauxhall in Scotland to £140 for BMW in London.
Steve Fowler, the group editor of What Car?, which conducted the survey, pointed out that a locum doctor charging between £350 and £500 a day is cheaper. Even a criminal law junior barrister will charge as little as £30 an hour, he says.
The report reveals that replacing a main-beam bulb on an Audi A2 can cost up to £66, with the bulb costing just £3.96. A full service on an Audi A4 can cost as much as £440 in London and as little as £220 in Scotland. For a BMW 318 a similar service costs £165 in Bristol, but £370 in London.
The cheapest car to service was the Ford Focus 1.6 - £110 in Scotland but £195 in London.
(old link I know)
http://www.independent.co.uk/news/uk/home-news/car-mechanics-charge-more-than-barristers-345941.html