You giving tip mean... you downgrade his job.

Specially in Car wash...

If you give he will wash nicely if not normal wash.... how disgusting...

Same in restaurant, if you are a regular customer... waiter knows you... if you are not giving tips.. he will not care you while he must care... because he is paid by employer to do the job.

I can hear someone shouting DO YOU KNOW HOW MUCH HE GET PAID.................Yes I do.

If you really wish to help someone.... help someone who you did not get any service from...

Tipping mean... you are bribing....