To rust-proof or not? The choice of whether to invest in rust proofing really comes down to how long you plan to keep your vehicle and if you like to get your top dollar at the time of sale. If you intend to return your car at the end of your lease then there is absolutely no point in paying for rust-proofing. For those who plan to drive their cars into the ground or keep them for longer, rust-proofing could keep your ride looking good for a bit longer and increase re-sell value. In any case, you should always consider the cost of rust-proofing versus the price of future repairs.