Rubber Seals

For those living in really harsh winter environments the weather sealing on (particularly older) cars can become more susceptible to deterioration.  Nextzett Gummi Pfledge Stift Rubber Care Stick is a good product to protect your weather sealing from drying and cracking, preserving the elasticity of your weather seals.

Here is a link to an article going into greater depth on Nextzett Gummi Pfledge.

Quality Paint Protection

Using a REAL ceramic coating, not just something with the word ceramic, will be a significant benefit to you.  But any quality protection whether it is a premium sealant or ceramic coating will help.  That help is in regards to the ease of cleaning.  When you are questioning what methods are preferable for washing in winter climates, that is the worst time to have dirt sticking to your paint.  A car that was properly detailed (surgically cleaned and protected), is a easier car to maintain in all environments.

Rinseless Washes

Rinseless washes, especially if the car is not very dirty, is a viable option.  A Rinseless wash solution can be thought of as car cleaning soap (alternative) that does not require a hose or flush of water.

Pre-Rinsing

I once did a two bucket traditional wash on my car with temperatures under 40 degrees.  Waterproof rain gear, in addition to thermal attire, helped tremendously.  I understand everyone is not wired this way.  If you can not handle performing a two bucket wash, I have an alternative.  I am not a believer in tunnel washes at all under any circumstances.  I am also not crazy about touchless washes either, especially if the paint and trim are not ceramic coated.  Part of the reason being some of those strong chemicals used with touchless washes remain on your car.  In addition to the lack of thoroughness of a touchless wash and the chemicals holding on to some of the grime, your car is still not perfectly clean.  I have seen cars stained from strong chemicals left on the paint.  My solution is, if you are going to do a touchless on a car in rough condition, use it as a prewash.  Treat the touchless as a presoak that also performs the heavy lifting of loosening up caked on grime.  When returning home or if you can pack your gear, follow up with a rinseless wash.  You are removing the remaining grime or film and also removing the alkaline and acidic chemicals remaining on your car.

I am not a fan of using waterless washes to clean an entire car unless absolutely necessary.  I will admit that compared to a tunnel wash, a thoughtful waterless wash is STILL a much better solution.

Bonus Tip

Here is an extra tip.  I believe this is a good idea for all seasons.  If you are parking in an area in which a neighborhood cat may enjoy being near your car, droplets of citronella can serve as a cat deterent.  I have put droplets of this essential oil (citronella) on concrete or grass to discourage cats from coming near my car.  Not just during the winter, cats may be using your car as a warm place to relax.  I find citronella to be a kind way of suggesting there are plenty of OTHER people who do not care about cats scratching their car.