If you want to give the motor home or caravan a complete makeover I can personally recommend " "tourershine" if you google it you will find the details, I had a 1999 Avondale given the full restoration clean a couple of years ago, not cheap if my memory serves me right at £300 but it was worth every penny, I had the same problem with dull paintwork and tried all sorts of polishes and waxes but although it improved with my efforts it was never particularly good especially on the front and rear plastic/grp panels which were really dull, a guy from tourershine spent around 6 hours working flat out but the result was outstanding, I reckon it looked better than when new, when I decided to sell it this year it was pretty grotty having been parked in front of house with us living in it with all sorts of building work going on, it was green with algae and loads of brick dust, a hose down and then a quick wash with some type of car wash wax, probably tesco own brand and it still came up far better than I'd ever been able to achieve prior to them doing it, our new caravan is shining great but I'm still tempted to have them come and do it because it makes life so easy in the future, various levels of service with varying prices so well worth a look, I will just say I'm not connected to this business in any way other than being one of their many very satisfied customers, not sure If this will get deleted as could be misconstrued as advertising but thought I'd give it a go.
BP