I shop at Aldi and Costco often so I would see Wiki Wiki all the time, but never stopped until a few weeks ago.
I was a little confused with the payment at the kiosk. Once I figured it out and paid it's pretty obvious where you need to go next.
If you are in need of a quick car wash - this did the trick. I liked that it was SO reasonable. I got my entire car washed for $8.
You clean your own mats (for free!), which is a little different, but I guess that's what kept the prices down. There are many stations to clean your mats, so waiting is never really a concern.
Give it a try!