The outcome of this damage? Lost dollars when it comes time to sell or trade-in your vehicle. But don't just take our word for it.

According to Kelley Blue Book, a 1996 Chevrolet Blazer with 45,000 miles described as in 'excellent' condition (glossy paint, no visible defects inside or outside, no rust, and in excellent mechanical condition) is valued at $6,835.

In contrast, this same Chevrolet Blazer is valued at 20% less in 'fair' condition (paint, body or interior may need work, rust damage may be evident, some mechanical or cosmetic defects need repair). In this instance, the trade-in value is $5,475.

The bottom line: Professional car washes and detailing services reduce wear and tear to interiors and exteriors of cars, which directly impact the value of your car. Visit Kelley Blue Book to see how your trade-in value may be affected by interior or exterior car damage.

Quotes from the experts themselves:

On corrosion caused by road and marine salts: "…general corrosion can result in perforations in the body and can reduce the resale value of a vehicle… personal driving habits and diligent maintenance of the vehicle, such as regular washing and replacement of fluids, can have a significant effect on the reduction of corrosion." (NACE study: "Cost of Corrosion")

On carpet appearance: "Any stains will reduce the value." (Kelly Blue Book)

On upholstery appearance: "Should be clean… It usually has some added value if it is in good shape." (Kelley Blue Book)