Is rustproof and paint sealant worth getting for cars in states with winters?

Long story short, I just bought a 2007 Camry. Now, my question is, should I be getting the rust proof and paint sealant for my car since I live in a state that has winters? I am not sure if it is worth it or not... Just wondering what most people think and if most people got it for their brand new cars as well. Everything, rust proof and paint sealant is around 600, not including tax at Toyota.Is rustproof and paint sealant worth getting for cars in states with winters?
I've heard it can be bad for your car. Sounds counterintuitive, but it was explained to me that the process can clog small drainage holes in the undrecarriage where water is engineered/designed to drain. Then if the water has nowhere to drain, it will sit and then start rusting. My toyota (a Scion XB) had 5 years/unilimited milage rust protection from the manfucturer, so I can't think it's a major threat-Is rustproof and paint sealant worth getting for cars in states with winters?
O ya, defintaly, i live in florida, and i have seen some bad underside of cars, when lifted into the air, there was a ton of rust.





Me and my dad had to replace a couple of parts for a guy who lived up north, and it wasnt cheap, it was making it gas lines and brake line rust and had holes. So just for a saftey, i would.
THE CAR COMES FROM THE FACTORY WITH A PAINT CLEAR COAT ALREADY, SO NO ON THE PAINT SEALANT.





YES FOR THE UNDERCOATING BUT IT IS TRUE THAT IF DONE INCORRECTLY IT CAN CAUSE DAMAGE BECAUSE ON SOME VEHICLES THERE ARE SMALL HOLES THAT WILL BE CLOSED UP.