Drive into petrol kiosk. Head for the car wash section.
Go through tunnel (most have some kind of enclosure). The folks
there will spray water first, soap second, and water to wash off
the soap.
They will ask you to move out of the enclosure.
They will wipe down you car, including opening the doors to clean
the side of the doors.
Most of them will end at driver's side and with the door open
someone will tell you that the job is done.
Price: Between $5 to $8 depending on car. Usually hatchback and
sedan is one price, MPV and SUV another. Taxi is usually
cheaper.
Don't pay till the job is almost done.