Sara,
I purchase a pair of automatic car washes a little over a year ago. These are a little different than the ones you are looking at since the only employee is me, and I only work part time when repairs are needed, or money needs to be collected.
There are countless things to talk about and answers to give. Two key pieces to me that i would suggest for you to consider are:
1. Who is selling. I was fortunate to have a seller who was very very helpful. He left nearly all the supplies/tools with the car washes. I can't imagine having to try and rebuild that stock. He also is helping to finance a percentage of the purcahse so he has some vested interest in my success. I didn't fully appreciate the value of this at the time, but it is huge looking back!
2. I would suggest you find out who the chemical (soap) supplier is and the maintenance person and talk with them. For me those two guys who incidentally helped physically build the car washes 15 years ago are a wealth of knowledge and advice. Reach out to them and buy them the fanciest dinner you can and ask their advice. That would be money well spent. (Maybe a steak dinner is a bit much, but seriously, they will know the good, the bad and the ugly.)
3. I am more than happy to answer other questions you may have. Feel free to reach out. My washes are certainly somewhat different than yours, but they are more similar than an apartment building.
Keep digging in, it CAN be a great business!
Dave