I am wanting to go for a 'Rat Look' with my new Beetle but am unsure of what to use to coat it with.

I am lead to believe that most people use a kind of tough wax to cover the whole car with so it has a shine to it and some protection to help the body last.

Is this correct and what should I get and where do I get it from please?

It's Ankor wax:

ankor wax info 

I've just done an original paint car in it and I'm really happy with the result! Just so long as you dont plan to re-paint it in the near future!
It has brought the colour back up on the faded paint and given it a waterproof skin like duck feathers! :shock: :lol: Now water 'rolls' off. The only downside is it does leave a thin greasy film kind of like you had covered it in Vaseline, which just loves the dust! But dust/dirt rinses off fine. I have given the car a water only sponge bath and comes up great again, the wax stays on.
You have to re-apply it every now and then according to your useage of the car.
(I am Waxoyling everything underside too)
The Ankor Wax is 'brown' which is fine on a dark car, but ask Tims advice before doing it to a white or pale car!
He's used it on a LOT of vehicles himself ( all those rat split buses!) and so I considered his actual hands on experienced advice was essential before doing this!

Tim at Roadhouse Retro £20 for 5L.

https://www.roadhouseretro.com/ 

---