Most people wash their cars when they get covered in mud, grime or salt—or if they attract the attention of a passing flock of birds.

When it comes to regular car washes, however, many of us miss the mark. That’s unfortunate, because having your car washed regularly is an easy, relatively inexpensive way to protect your vehicle, yourself and your investment.

There are several reasons to get a weekly or bi-weekly car wash, even if you’re driving through city streets and under bird-free skies. Here are

It protects your paint. A regular wash and wax will protect our car’s paint, not wear it down. The fact is that the dirt that vehicles gather as they move about—even over seemingly dry, clean roads—can be very damaging if left to bake onto a surface.

It increases fuel efficiency. Believe it or not, dirt will slow you down and cause wind resistance on an otherwise slick surface. You may not think it makes a significant impact, but any automotive engineer will tell you otherwise. Over time, the increased drag of dirt or other residue will impact your aerodynamics. Studies have shown it can decrease efficiency by as much as 10 percent. Consider the swimmer, who shaves excess body hair, or cyclists—there’s a reason they wear those slick, silly shorts.

It protects your body. Dirt, salt and grime will not only hurt your paint, it could damage your underbody, frame and engine. Add a semi-regular engine wash with your regular car washes to protect your motor.

It improves safety. Dirt and debris can build up on your windows, impacting your ability to see and causing damage to your wiper blades. Even at moderate speeds, a blotch or smear can cause a dangerous blind spot.

It shows pride in your vehicle. Clean cars look newer and better cared for. A regular car wash will also help you make a better first impression at work and while socializing.

It will improve the resale value, particularly if you sell the car to a private party, rather than training it in to a dealer. If a perspective buyer thinks the car is well-maintained—as evidenced by a regular car wash, he or she will be more likely to meet your asking price.

It can help keep you healthy. We spend a lot of time in our cars—and so do our germs. Think about every you sneeze or cough behind the wheel and then multiply it by the number of times you’re out interacting with the public and trailing their germs back to your driver’s seat. A regular disinfectant along with your car wash can kill those germs and keep you sniffle-free.

It’s just as important to keep your car looking good as it is to keep it running good and driving straight. Add a weekly or bi-weekly car wash to your maintenance schedule. It’s a relatively small investment that can pay large dividends in the long run.