Having a fresh, dry car interior is like having sweat-free armpits on a hot summer day, if you know what I mean. The thing is, summer is over and the rainy season is now in full swing, and just like wet armpits, if your car accumulates or traps moisture you'll end up with bacterial growth and undesirable smells ranging from wet dog to dank mop.
If you don't have a clue regarding how to keep your interiors less prone to moisture, I have a collection of tips and fixes I've used for years. It will take some effort and money, but this is certainly well worth it!
1) Dehumidifiers and desiccant. I'm sure one of my fellow Top Gear teammates has suggested these before, but I'll throw them in nonetheless. These are staples for minimizing moisture build-up in a very economical way.
For dehumidifiers, make sure to get the short-standing versions so they don't topple over and easily fit under your seats. The combination of collected moisture with the granules inside forms a slick liquid. Replace once all granules have dissolved.
You can also use some good old charcoal or uncooked rice if you don't come across the aforementioned.
2) Using your car's heater. If you've been driving all day in the rain, there's a good chance extra moisture may have built up in your car and A/C vents. As soon as you've arrived home, switch your thermostat setting to max heat and blast your blowers while slightly opening your windows so all that vapor can escape. This results in a drier interior. Do this for about 15 minutes. Don't forget to unclip anything attached to your A/C vents such as air fresheners.
Are you familiar with that musty smell the moment you just turned on your air-conditioner at the start of the day? This should help avoid that.
3) Investing in good floor mats. It is very important to keep your vehicle's carpeting in tip-top condition to avoid corrosion beneath, costly carpet replacement, and bacterial/mold growth which can be detrimental to you and your passengers' health.
Acquiring a set of precision-fitting deep dish mats is a great way to keep your carpet dry and keeping your cabin's atmosphere fresh. There are quite a few options out there to match your budget.
4) Avoid leaving wet items inside your car. Whether it's your trunk or cabin, never leave soaked clothes, footwear, raincoats or umbrellas in these areas as they can invite the stink monster inside. Always have a designated spot or container for these and never ever procrastinate on tidying up your cabin at the end of each trip, or day for that matter.
5) Check your cabin filter. A neglected, dirty cabin filter could also be a culprit for foul odors, as the combination of dirt caught in its cavities and increased moisture create a breeding zone for bacteria. Replace as needed.
6) Using disinfectant/deodorizing sprays. I just love how we have more options for cabin care these days. After being bombarded by relentless rainfall for weeks, treat your interiors and A/C system with a disinfectant/deodorizing spray. Simply switch your air-con to high with closed circulation, situate the spray on the floor (usually in the back row with the front seat moved forward), engage the spray nozzle until it locks open, and wait 10-15 minutes or until spray runs out. When finished, open doors/windows to allow ventilation for a few minutes and you're good to go.
I've used this type of product for years now with favorable results. These are usually available in automotive sections at major hardware stores.
7) Fabric protectants. After a good interior detailing, it would be wise to treat your upholstery and carpeting with good fabric protectant. Be generous with the application as this gives your fabrics and carpet a repellent barrier from absorbing unwanted moisture.