I live in Vermont and have two Subaru Outbacks. One is a 2010 Outback and it has been suggested that I have the undercarriage sprayed with a waxy coating to help prevent rust.

The other is a 2001 Outback Sport that has small rust spots forming at the rear tire wells. It has been recommended that I have oil sprayed into the body of the car by drilling a hole in the door frame. I am told this will greatly slow the rust process and then to have the spots repaired in the spring.

Any thoughts or advise on doing these two things?

I wouldn’t, oil won’t slow rust once it starts, and can even make it worse. Your new one is already pretty rust resistant, and sprays can also make it more, rather than less, likely to rust.

New cars really don’t have a need for aftermarket rust preventative treatments, even in Vermont. The body will outlast the engine/transmission guaranteed, even if it does have some rust at the end of it’s life.

Nope… they want a boat payment from you…The best thing you can do is during the salt-season is to wash the undercarriage…auto car wash or do-it-yourself…after-market undercoating can void your rust warranty…