上空洗车

• ⺊(dot above; high position)ASSOCIATIVE
• 一(standard baseline; norm)ASSOCIATIVE

A dot mark sitting above a horizontal line represents the meaning 'above'.

• 穴(row; gap)RADICAL
• 工(craftsman; work)PHONETIC

An empty cave with nothing inside is just hollow space.

• 氵(water; liquid)RADICAL
• 先(before; lead)PHONO-SEMANTIC

Washing uses water going first to clean everything.

• 車(vehicle; chariot)ASSOCIATIVE

The character 車 is an ancient picture of a vehicle viewed from above, showing its axle and wheels.