This Sumeer I intend to provide the underside of my car wings a treatment that will help forestall the onset of rust. Presently the wings are in excellant condition and the undersides are presently painted in blue undercoat with no damaged areas.
Recommendations please for 'best product', I shall be applying the material myself.

I would recommend Waxoyl . I have been using it for many years . I treated myself to a good quality spray bottle to apply it. On my box saloon which has spent much of its life outside has no rust underneath, Every couple of years or so I lightly brush the underneath and apply another coat I also spray the wells bases of my wheels. if applied where the tyre pinches up against the rim when inflated none of that nasty rust, that commonly appears, will form.The can should be warmed before applying.