Hello. I have owned my 350z for about a year now and when I bought it, it was rust free. I did drive it a little bit during the winter when the roads were dry but I guess some road salt got on the undercarriage. Rust spots has started to appear here and there but the worst of it is above the front driver side wheel (Couldn't get a good pic) and driverside of the crossmember. As of now it's not too bad and is just surface rust but I know it can get worse if not treated so I'm wondering what would be the best way to treat this? Thanks in advance!

 

This is the time honored best rust removal/protection stuff: https://por15.com/

I used this on a car that was brought in from out of state decades ago and in the 8-10 years I owned the car, rust never reappeared. Sure, could be that I'm in dry California (not just cuz o'drought, ehh) but it worked to remove same type of rust. I did a thorough job by wire brushing it, applying POR-15 rust remover then cleaned and painted with traditional primer and paint. POR-15 offers their own paint now as well.

 

Vinegar. Youtube it

 

I will second the POR 15
You can buy the kit that has all the steps included
Amazing stuff