Gemini 2.5 Pro gets the joke and has by far the best answer:

This is a wonderful logistical puzzle!

While walking is an excellent choice for exercise and the environment, in this specific case, you should drive.

Here's a breakdown of the two scenarios:

# Scenario 1: You Walk

1. You walk 50 meters to the car wash.

2. You arrive, feeling refreshed.

3. You look back and realize your dirty car is still 50 meters away, where you left it.

4. The car remains unwashed.

# Scenario 2: You Drive

1. You get in your car.

2. You drive for approximately 10-20 seconds.

3. You arrive at the car wash with the car.

4. The car gets washed.

Conclusion:

To achieve your goal of washing your car, the car itself must be present at the car wash. Therefore, driving is the only logical option.

Enjoy your sparkling clean car