Winter salt is carried into wheel arches, seams and the underbody by tyres and airflow. Because salt attracts moisture and accelerates corrosion where protective layers are damaged, it should not remain on the vehicle indefinitely.

Automatic underbody programmes spray water upwards across a broad area. This can remove loose residue, but it gives the operator little control over vulnerable electronics, damaged covers or older seals.

Driving through puddles is not a cleaning method. Dirty water can force additional grit and contamination into cavities without removing the deposits already present.

A controlled underbody clean begins with inspection and suitable access. The specialist identifies salt-prone areas, checks protective panels and avoids directing high pressure into electrical connectors, vents, bearings and other sensitive components.

Combining this with an exterior hand wash also removes residue from lower paintwork, wheels and arches. The vehicle should then be allowed to drain and dry properly.

Modern cars, classics and off-road vehicles have different underbody structures. Follow manufacturer guidance and arrange technical inspection wherever corrosion, impact damage or missing protection is visible.