OK i just read up on POR15. It sounds too good to be true. Now I'm going to have to ask. What is best. tetroseal, Waxoil or this stuff???

If you get a chance to dismantle the vehicle completely and clean the chassis down to bare metal all over then POR 15 would be a good idea. Assuming you don't have plans to do that in your schedule any time soon, then some sort of spray on treatment that can be applied with the chassis in situ might be better. Personally, I favour Dinitrol but something that provides a tough coat on the outside of the chassis and something thin and runny with a good deal of 'creep' to spray inside the chassis through the holes would be good.

A garden sprinkler on the end of the hose, slid under the Landy, will get on with the rinse down while you have a cup of tea!