Originally Posted By: Kestas
Even with corrosion present, the car would benefit from rustproofing. Now is a good time. With a good wash and drying, the compound will do a good job seeping into the nooks and crannies during hot weather.
I agree 100%. If the vehicle is already/somewhat rusty, the rust proofing will stop it dead in its tracks and will adhere a tad better as well.
Warm/hot weather is best, I agree. Most wait until fall/winter but it is actually the worst time but is still far better than not doing anything at all.
Originally Posted By: Schmoe
I wouldn't rustproof now until you're absolutely sure you got the salt out, or you'll just be locking it in. I wait until you get a torrential rainfall and drive through as many water puddles as you can. Salt will dissolve in fresh water.
I disagree. The undercoating, if a recognized oil spray such as Rust Check or Krown is used, will stop any further rusting dead in its tracks.
If, by some slim chance, the OPs vehicle is still covered in salt underneath, then just spray everything down good like I mentioned with a garden hose on the shower or stronger setting.
One should do this prior, imo, anyways, as you want to get dirt/clumps out from underneath if you can. Of course this would mainly apply to someone who has been down dirty muddy roads but taking a fairly clean car to any rustproofing place is recommended.