I own a Subaru Legacy Limited 2.5i 2011. It has about 129000 miles on it. I live in the frigid state of Maine where the potholes are aplenty and the snow is too! I've owned this vehicle for about a year now as hand-me-down from my stepsister. I'm 19 and a broke college student so I'm not sure what to do about the rust! It's getting pretty bad, and it is all underneath the vehicle. I'm not sure if I can afford a new car right now so I'm wondering what I should do to fix it and how much it would cost. It's also gotten to the exhaust system and has gotten really bad, the mechanic I took to get it fixed when the rust broke the piping said it would take 3000 dollars to fix it. They were able to help me out however and do a patchwork job by welding some piping they had to the exhaust pipes to fix the leak. I've noticed its starting to leak again. What should I do? I've heard rust can destroy a car, especially if its on the underside of it, and it really scares me, as I need it to go back and forth from my Dad's place to my college to pick up important tax mail, like W2s. I live on campus but I do drive a good amount as I have to commute between campuses (My college has three campuses.)
keep it clean and cross your fingers
My friends 2005 F-150 was rusting pretty bad, the bed supports are in pieces by the ends, moderate to heavy rust by tires especially.
I bought 6 cans of cosmoline for about $50, I hit the rust with a wire cup brush cheapy from harbor freight on a drill, enough to knock the heavy stuff off, I also used a small steel brush for the nooks and crannies, and hit it with CRC cosmoline. The cosmoline will choke the rust, and sits on it just like wax, potentially for years, or decades if nothing is hitting it.
I reduced at least 90% of the rust, and will finish the rest in spring. It took a bit of work, but now the truck will at least not die from rust. I use the same stuff on all of my cars.
There are other options, but if you do nothing, the rust will win for sure.
This is an interesting comparison of some of them.
https://www.youtube.com/watch?v=lyWHF4NoNVk
Can you show us some pictures? If the car is structurally unsound it needs to be removed from the road but hopefully it is not as bad as that. Are you able to poke holes in the rust with a screwdriver?
If it's just surface rust you may be able to preserve it for a while by spraying underneath with something like Fluid Film or even old engine oil to slow the corrosion. Rust never sleeps though so you need to start preparing to replace it.
