Local carwash convinces woman to spend extra $4 for a service she never heard of. Turns out, it’s how you save your car

A viral social‑media post is drawing laughs and unexpected car‑care wisdom, as TikTok creator @Ashleyesper (Ashley Esper) recently shared how a spontaneous decision at a local carwash turned into a surprisingly savvy vehicle maintenance moment.

With text overlay that read, “Was just convinced to pay an extra $4 to wash the bottom of my car and I’m not really sure if that’s really necessary but the car wash guy was so enthusiastic about it so if he’s happy, I’m happy.”

She captioned her video, “Sucker for a good sales pitch,” but commenters were more interested in the practical side of that extra $4 add‑on, especially in the winter months.

Is a “bottom wash” really worth it?

“A clean bottom is always important,” one commenter wrote, and car‑care professionals agree. Multiple automotive guides note that regular undercarriage cleaning can remove corrosive agents before they cause damage, helping extend the life of vehicle parts that are otherwise out of sight and often ignored.

Car undercarriages regularly accumulate road salt, brine, dirt, and grime, especially if you drive in areas where streets are salted to prevent ice. These substances don’t just make for a dirty chassis; they accelerate corrosion and rust on metal components if left in place for too long. Rust can lead to costly damage to brake lines, fuel systems, suspension parts, and other key systems under the car.

Winter driving makes undercarriage washing even more crucial

Responding to Esper, several commenters chimed in with firsthand seasonal advice. One wrote, “As a car guy it is very important in the winter to do the underbody wash. The bottom is usually the first place for rust starts because dirt and salt gets trapped under there.”

Another said, “It’s actually really important to do. The salt and brine just eats away at the bottom of your car. You should always wash it off a few times a season,” while another noted, “It’s important in colder states when they salt the streets because it can eat at your car!” and one added, “Best $4.00 you could ever spend.”

Even guides from carwash industry groups highlight that removing road salt and grime from the underbody protects metal components from corrosion and extends vehicle life, which can help maintain vehicle safety and resale value.

So what’s the “bottom” line?

So, while a basic carwash might clean visible surfaces, an undercarriage wash targets parts of your vehicle that are especially vulnerable in winter and in regions where de‑icing salts are used, and Esper made a good choice. Paying a small extra fee — like the $4 Ashleyesper spent — for that bottom wash likely helps protect your car over the long run, rather than being just a frivolous upsell.

For drivers who live in climates where roads are salted, or who simply want to preserve their vehicle’s metal underpinnings, regular undercarriage washing is not just a clean bottom line — it’s good maintenance practice.