To be honest Farnsy its all in the prep, a wax is just wax but as long as you spend the time on the prep you will get the results your looking for I would say the wax is your last 20-25% of work to getting your paintwork looking good, a good autoglym product I did use was HD cleanser, I have used HD wax yes its good and I have used Dodo juice, Purple haze, Rainforest rub, blue velvet and orange crush and Mequires synthetic wax as well.
HD and Dodo are about the same for the length of time that last before they start to drop off a bit the Meguires lasted a month or so longer than the other two as it is synthetic . I am always up for trying new stuff to see how it preforms and spent loads on different waxes but a friend of mine said try armour all from boyes its a tenner a tub and it is brilliant stuff I thought yeah yeah gimmicky like the showroom shine stuff but he was right it is good stuff and the beading and sheeting is as good if not better than the waxes I have used at the moment it has lasted through winter, I wash my car nearly every week after your wax you also want to get a decent shampoo for it that will not strip all your hard work your about to put into the paintwork.
Dave