How can we protect our car from corrosion cause by rock salt?

Living up North our roads can be liberally sprinkled with copious amounts of corrosive rock salt. I do believe it has become a 'finer' salt that is used today, hopefully causing less bodywork damage than the ghastly old orange coloured stuff which really did resemble 'rocks' and more readily damaged your paintwork before getting to work in earnest on the underside. Having said that I am sure vehicles will be far better protected than they were say a decade or two ago, particularly in obviously vulnerable areas.

Do you have any general advice and/or assurances on this specific aspect of winter motoring, long-term vehicle integrity and safety being absolutely paramount? Or do we have to try and replace the car every three or four or five years before the corrosion gets hold? Being semi-retired we try not to use the car when the roads are covered in ice and snow or when freshly gritted or (much) more so when it has rained on 'salty' roads,

Asked on 20 January 2020 by Maltozo

Answered by Andrew Brady
Modern cars have far better rust protection than they used to but you do still hear of some models picking up MoT advisories for rust at a surprisingly young age. If you're worried, it might be worth investing in having your car undersealed - this is effectively a thick paint which can be applied underneath the car to protect it from road salt. You can also buy extensions for pressure washers which are designed to clean underneath the car.
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