Highest & Best Use
I understood your inquiry as being directed to structure that best positioned your business to be valued, if you chose to liquidate at some time in the future. Accordingly, I offered some suggestions that would apply to all of the methodology for assessing value.
We all know that the market ultimately tells us, at that given moment, what the value of anything is. Yes, it is the supply versus demand axiom. But when you position yourself to sell, most buyers seek the kinds of justification that your original question begged, and that's why the structure of your multiple operations may demonstrate the diversity.
Most operators would agree that at some point, "everything" is for sale... and has a price. When that time comes, you'll benefit more if your argument for higher value is supported by something other than a real-estate/carwash consultant lumping everything together.
Bud is correct when he says that there is a buyer for everything. And, yes... timing is everything!
Accordingly, the key for optimizing the transition is how well you can "market" the site's perceived value. A skilled salesman appreciates all the "tools" available to maximize a purchase. I simply suggested a few more that might make a dollars & cents difference. At least, that's been my personal experience.