On our recent trip up the Oodnadatta Tk and the Centre I made a point of WD 40 in the rear door lock mechanism and catch every night.
We had a heap of dust and stack of mud due to rain betwen Oodnadatta and Marla ( 20mm rain overnight )
As others have pointed out WD 40 may not be the best long term option but as sson as it started feeling tight I lubed it up good with WD and had no troubles. I may clean him out now and use Graphite Powder.
Someone also told me to use Mr Sheen or another silicone based spray can cleaner in locks and mechanisms after graphite powder as this will carry the graphite right in and leave it when dried out.
Pete

