Krown is popular up here in Canada...However, I use a local chain in Quebec called "Metropolitan Rustproofing" --> http://www.antirouille.com/en/
Their product is Mineral Oil based with some additives...I service all of my vehicles annually (in the Fall) for about $80 and I have been extremely satisfied.
I also own a 1997 Pathfinder that has been serviced annually - 10 years, and there is virtually NO rust under the carriage. My doors are like new (typically here is where the rust is more noticeable). And tks to this procedure, removing bolts, screws, etc..is a piece of cake..
You have to keep in mind that in Quebec, the city and transport ministry ENJOY using SALT/CALCIUM on the roads like there is no tomorrow.
What I also do prior to "shooting" my cars with oil, is that I use a Electric Pressure Washer to remove any soil/dirt etc..from the bottom of the car, around the fenders, bumpers, etc..I make sure that the surface is clean, wait a day or two to ensure it is properly dry, and then "shoot" it with Oil.
I hope this helps..