Leaves and cars don’t mix. Although they’re beautiful, leaves damage paint, cause rust, plug drains and in general make a mess of cars.

First is paint damage. Leaves, moisture and sun can seriously damage today’s clear-coat finishes. You know that the acid in bird droppings damages paint, but did you know that leaves contain similar acids, which when mixed with water and allowed to bake in the sun can etch clear coat paint surfaces? It isn’t unusual to find an ancient, fossil-like outline of a leaf permanently embossed into a car’s paint. Unfortunately, the only way to prevent this is to remove fallen leaves as soon as possible.

Leaves also cause rust when they become trapped under moldings and in body crevices. Once leaves are caught they may not go away until you reach highway speed, where the wind causes the leaves to flap back and forth until they break.

But although it appears they’re gone, the leaves may be only partially gone. The wind causes them to break into pieces with the larger, more visible portion left along the road while a smaller piece remains trapped on the car. Over time what remains is joined by other bits of dirt and leaf debris. When the car gets wet, trapped leaf parts soak up moisture like a sponge and hold it against the metal. This eventually leads to those ugly rust blisters around moldings and windows. To prevent damage, use a garden hose to thoroughly flush away all the dirt and debris that collects behind moldings, in body seams and cavities at least twice a year.

Another problem with leaves is they clog car drains. The evaporator drain for the air conditioning is a common problem. Leaves are sucked through the heat and air conditioning air inlet where they’re promptly sliced and diced by the blades of the fan. Then the minced leaves collect in the bottom of the evaporator housing where, over time, they decay into a thick paste that plugs the drain. Eventually, this causes water from the air conditioner to spill onto your feet or carpet inside the car.

If your car has a sunroof, you might also experience a wet head thanks to leaf debris. Sunroofs have drains that can be stopped up by leaves. Contrary to what you might believe, sunroofs are not watertight. By design, some water flows around the glass, collects in channels that guide it into drains positioned at each corner of the sunroof. Clogged sunroof drains allow water to build up in the collection channels until it overflows into the car. The overflow is often in the form of a startling gush of cold water onto your head as you round a corner. Sunroof drains need to be checked once or twice yearly to avoid problems.

Keeping leaves off your car is an important part of proper maintenance that takes a little effort but saves a ton of grief.

This special advertising section was written by Pat Goss, a freelance writer, in conjunction with The Washington Post Custom Content department. The production of this supplement did not involve The Washington Post news or editorial staff.