I'm buying a new 2015 Toyota Camry. Is it worth it to have it rust proof if I intend to keep it many years?

If you live in an area where they use salt in the winter for snow removal and it would be out in the weather instead of in a garage I would get the rust proofing.

Almost all near cars (except ultra cheap ones) are pretty rust resistant. I see 97-01 Camrys on a daily basis with minimal to no rust and I'd assume the new Camry would be even more rust proof

I bought and still own a 2006 Toyota Prius. Part of this cars warranty is rust free life time warranty-Toyota motor corporation. Call/pay your local toyota dealership a visit

Even if you kept it forever it would be a waste of money. Modern cars already have very good paint and rust protection. They come with a rust warranty that if very good. Additional rust proofing does nothing but take your money.

If it comes from the dealer, with a rust warranty.. buy it. And adhere to their maintenance schedule, for the rust proofing (it should be free). If you live in southern states, don't buy it. If you live in salt infested roads (winter), I highly recommend it.

That's a complete waste of money. The factory "rustproofing" is more than sufficient to last the life of the car. You would be paying the dealer for unnecessary garbage.

I would suggest undercoating, I was told by several service advisors that the underside is where most rust starts.