Under body paint / ute liner

[Black-Pig]

Hello All.
I am looking at painting on some ute liner type stuff to the under side of my camper as most of the paint is now not there.
I think I will spray on some kill rust first, but just wondering what people have done or plan to do.
I will also be looking at something for the inside of my trailer too, and possibly my ute.
Option? I know there is a product in supercheap called noise killer which is like a tar type thing and also rhino / herculiner as options.
Plus show me your DIY results as  ...

[oldmate]

Ultimate use Upol Raptor on their trailers.

But you could use stone guard. Sika 552 would be fine
http://aus.sika.com/en/solutions_products/01/01a001/01a001sa02/01a001sa02100/01a001sa02106.html

Or
http://www.supercheapauto.com.au/online-store/products/Septone-Stone-Shield-Anti-Chip-Coating-Black-1-Litre.aspx?pid=33204&menuFrom=80408#Cross
Sprayed with one of these
http://www.ebay.com.au/itm/251560971817

[edz]

Personaly Im not a fan of hard type coatings, reason being if you get any openings in the coating you can get moisture or salt / dirt etc build up in behind it out of sight and end up with hidden rust problems ..
If its for stone rash I'd be more inclined to protect with some form of removable shielding. 
More inclined to go with a good clean and coat of paint each year or so, assisted with a penetrating oil like lannotec or a soluble oil before / after a beach trip and after a good clean from a dirt  trip ..
A bit more work than just coating it and forgetting it, I guess it depends alot on where / how you use it and how long you plan to keep it.