Winter Parking!

[jambo101]

Up here in Canada we have many outlets for an oil spray rust protection procedure,takes about a half hour to apply and costs around $100,
heres one=
https://www.krown.com/process/
And another=
Metropolitan Rust Proofing | Preventive Treatment Against Rust

There may be something equivalent in your location that supplies an oil spray process.
Avoid hard plastic undercoating as after a few years the plastic cracks and becomes prone to many areas where salt can accumulate..

[BostonMike7]

My infinti came with a factory type of undercoating on all underside panels. A lot of the suspension is aluminum as well.

in 160K miles, driven through salt and snow frequently, only the exhaust has faired poorly. I might need to use some PB blaster on certain bolts here and there, but nothing has stopped me from routine maintainence on the underside.

Only rust related repair in 160K miles has been $40 to cut and reweld a rusted muffler flange.