basicaly wash your car as normal and rinse off, while the car is still wet go round the whole car with a diluted mix of demon shine in a sprayer( i mix around 150ml of ds in a 500ml bottle with normal tapwater) once you've misted the whole car roughly you can proceed to dry as normal and much quicker too with no streaking, you still have to wring the towel out obviously but the demon shine helps it absorb quicker,
yes megs qd is fine mate
i only suggested britemax qd because its a very good product and leaves a nice gloss and is very economical to use, i use this if i havent got time to re-wax.