Washing the Van

You do not need those products. Some contain TFRs or Traffic Film Removers which are damaging.. Just use a mild mix of car shampoo and warm water..

I've used Muckoff to get the worst off especially the roof. It made a good job, followed by a polish.

Hi Dave,

Hope the Norfolk trip went well and you are pleased with the van.

Muc off can be had in the Halfords cycle section. I am not certain if it is ok on the van. Worth checking their website.

I reckon the Rienza has a more tolerant body being GRP. I always used Fenwicks Motorhome cleaner (they also do a caravan cleaner) this is also sometimes available in Halfords. I used to finish off with Fenwicks Bobby dazzler ( a  finishing wax ?). Both are readily bought in a dealership with an accessory shop.

The worst part is doing the roof, especially under the solar panel. I used to get on the roof (90kg) and provided I moved carefully I walked about with hose and brush. Don't put any weight on the over cab section as it is very thin and flexible.

Davy

Mucoff is available for bikes and caravans (maybe same product with different labels). I won a pack of the Caravan version, it came with a microfibre mitten which was great to agitate it on the muck.

Muc-off is quite expensive for what you get.
I've been using valet pro citrus degreaser on my cars paint work and it is a great product.
There is also a product called Fenwicks caravan cleaner which I have heard a lot about on mountain bike forums but I have never used.
5 litres of the citrus degreaser is about 20 quid and should be diluted down 1:5 for tough dirt and 1:10 for general use, so it lasts pretty well too.

Fenwicks washing products for me, followed with a good polish.
Boaby

Muck off do a product for vehicles but it's Pricey for the qty you get... I've used Fenwicks motorhome cleaner and would say it's a better product and much cheaper per wash.

I currently use products by a company called Chemicals Direct, they do a lot of marine products also, their motorhome cleaner is highly concentrated and although it may appear Pricey you only need a capful so it just lasts forever! They also do a motorhome wash and wax with Carnauba

You can buy their products direct as they have an eBay shop here http://stores.ebay.co.uk/Chemicals-Direct-Ltd/Caravans-and-Motorhomes-/_i.html?_fsub=3055433014

Delivery is 24-48hrs and they are friendly and helpful in my experience, one of the mags think it was MMM reviewed their cleaner sometime ago and rated it very highly too.

I don't think I'd use anything else as it's just so good.

CC

That product looks pretty good CruisingComet  Might give the one with the wax a go.  I have been using Autoglym wax and wash for the past thirty odd years without any issues but always worth trying something else. 
I have been wary of the Fenwicks; albeit a fantastic cleaner I worry about its corrosive/chemical content. I washed my new Avondale caravan with it and it turned the false chrome on the wheel trims green and they started to flake off within a week. I had  (I thought) rinsed it off thoroughly as well.  Having said that, their liquid polish is brilliant.