Car washes, in general, are a “scam.” The only time I use one is during the winter to get the mag chloride off when it’s too cold to wash my car by hand.
I’ve been hand washing ever since I’ve been driving. All you need is a bucket, hose, cotton wash mitt, sponge, and drying cloth. Go to your local auto parts store and buy them all for less than $20. They will pay for themselves it within a few car washes.
Google “how to detail my car” and you will see step-by-step instructions. In general, I don’t use car wash soap as it removes the nice coat of wax I put on twice a year. I only use soap once in the spring and fall, just before clay barring and waxing my car. Other times, just pure clean water.
Avoid automatic car washes.
They recycle the water – good for conserving water, bad for your paint. The filter removes most, but not all, of the dirt. The remainder will sand blast your paint.
The swirling brushes are even worse – like scrubbing your paint with a brillo pad.
Spray the under carriage of your car and wheel wells. Wash and dry it by hand and it will look great. My 15 year-old BMW still looks like the day it rolled of the show room.