Most paste waxes have gone the way of the dinosaurs by now. True ceramic coatings (the ones that come in little glass bottles with suede applicators and specific instructions) last longer and are actually easier to apply, IMO.
One thing I don't think is talked about enough is that an inexperienced detailer (or even experienced ones that don't know any better) tends to cake wax in every little crevice and crack on the car where it dries to a white chalk that you have to dig or scrape off every panel, or they get some on rubber/plastic trim and it's very hard to remove. You can make a similar mistake with a ceramic coating where you might leave a "high spot" where the coating flashed off but wasn't wiped off the panel, but you can remove that in 10 seconds with polish and a microfiber cloth, and ceramic coating on rubber/plastic can actually make it look better (deeper black) and protects it. There are coatings for wheels and glass windows as well which are well worth it.
There are hundreds of ceramic brands since they're cheap to manufacture and have a high markup, plus everyone wants to use them. Typically if you're paying ~$60-100 for a 30mL DIY kit that's not a made-up Amazon brand then you'll do well, not that I've tried a $15 Amazon special kit but if you're spending the time to do this then I think it's worth spending a bit for something you know works well. My personal preference is Carpro (Cquartz) for most things, there's also Gyeon, Sonax, 3D, Gtechniq, and Optimum as some respected brands. There's also graphene-infused coatings which are even newer than ceramic and therefore more expensive, I've not tried one yet. Ceramic detailing sprays are also popular and easier to apply than a true coating, but are meant more as an "every other wash" type of thing, they don't last as long.
Pro detailers have access to specially-made "pro grade" versions of the above coatings, I'm not sure if that's just marketing hype or the coatings are actually formulated differently for flash time/durability. Detailers obviously charge for their labor which blows up the price of a ceramic coating to >$1k USD because they should be polishing the car before applying it, which can be an all-day job.
If you prefer to DIY, there's a whole big rabbit hole to go down but to stay sane you can just wash the car, decontaminate it with an iron fallout remover spray, clay bar, perform a 1-step quick polish if you have the time/tools, and then coat with ceramic once the paint is completely bare with no waxes/oils/etc. The polishing step isn't strictly necessary but that's how you get the best coating durability, plus the paint underneath will look way better in the first place. If the car lives inside and your climate isn't Russia, the coating will last a few years with some basic care. Like DRIFTER says, once this is done properly, you can foam up the car and just rinse & blow dry it off and it will look better than 99% of other cars on the road.
To answer nigel's original question, the real key is to perform the above steps and then it doesn't really matter which car wash soap you use as long as it's not meant to strip protection off (bug removers, etc.) and you like how it smells. I personally prefer a pure soap over a combo-type like Wash & Wax which leaves some wax on the car, if you use that before trying to polish or ceramic coat paint it can make your life difficult. I like Chemical Guy's green car wash soap since it smells like melons
. Meguiar's Gold Class wash is absolutely everywhere but smells like ass to me so I don't like it.