I would not recommend G&N. They told my wife her car needed a new clutch and then forgot to do it when she booked it in. They did not apologise for forgetting to fix the car even though they knew she was relying on them fixing the car as she had to do a long drive th next day. Then she took it to another garage who said that the clutch was fine and didn't need replacing. That was 2 years ago and clutch is still fine! So they don't tick the friendly or honest boxes from our experiences.
A tentative endorsement for Hi Tech. Tentative since I have just come back from using them only to get an indicator light bulb changed. But an endorsement as the first garage I took my car to told me I'd have to take the car in to Audi (and no doubt pay and arm and a leg for the privilege). Hi Tech were friendly and did the job I asked them to - even though it took three of them to work out how to remove the light unit - and they only charged me £5.
I would certainly recommend Hi Tec in West Green Road as they are very friendly, do an honest job at low cost and don't 'invent' jobs just to inflate the bill. I've been taking my wife's 22 year old Sierra and my own 40 year old Rover there for years.
I'd like to recommend Jewels' garage on Victoria Road - 020 7561 1392. I've been going to them for almost thirty years and they are the nicest of people, and very good with older/ailing cars.
Also, for tyres, the guy at the top of Burgoyne Road has been very good and cheap.
Good garage in Tottenham - contact Tom Theodoulou on 07801457046.
Has been doing MOT, service, etc, for my (now very old) car for years.