Guitarandy,
The single most important thing you can ever do for your wash is a proper and thorough due diligence.
I built a wash a little bigger than you are proposing and I agree with all the posts so far...but are you willing to listen? So here goes my 2 cents;
First, when I researched mine I looked at it five different ways. I counted cars are competitors, took the sales info from the vendors, etc and it took me 2 years to pull the trigger. I had a few 'what if's' in there for good measure. My numbers checked out and I was going to make a mint, then two other competitors build and blew my numbers away. Fortunately I have the best location. So don't wear rose colored glasses when looking at this.
Second, 2 small old self serves washes and 2 with 5 ss , 1 IBA is not light competition in a small town of 14K pop. Depending on where you are exactly, that amount of competition would scare me away completely. Here's a what if...what if Wal-Mart builds a car wash...what will that do to your $700K?
Lastly, do you truly understand the business. It's 24/7/365 going concern. Do you have the technical aptitude and business acumen to pull it off? Look in the mirror when you answer that one, because it's anything but show up and collect the money. I have over 30 years in the technical world and I pride myself on being able to fix anything...my wife is an accountant and her skills are very much required. So it works for us. Still, it ain't easy.
All the best...BigLeo