I had an idea of marking the spot in some way. On the concrete pad, it was easy and we purchased a box of sidewalk chalk and marked the places the tires were in on the spot that was level. This does not work on a gravel or dirt site. There is nothing that the chalk will mark. I decided to find a more universal solution.
I started looking for what I could put down on the ground that would not interfere with pulling the Roadtrek in and out and what would remain (as long as no one took it) when we came back to the site each time during our stay. I looked at a variety of things that might work. I started with flat metal bars and decided that they would work well, but I wanted something that would not rust and would be a more convenient size without having to cut anything down. In a store, I walked through the hardware aisle and came upon something that in construction and woodwork are called mending plates. They came in galvanized metal and also brass. While galvanized metal is not supposed to rust, brass will not rust and even though the brass ones cost a dollar more, that is what I settled on. I bought a package of four inch, straight mending plates that are a half inch wide. I also purchased a roll of yellow reflector tape. I chose yellow over red as I felt that the yellow would show up better in the dark when pulling in - even with the help of a flashlight. Below is a photo of what I made -
The reflector tape was one put on the top of the mending plate and turned over the sides with a good overlap on the bottom to hold it on. I took a piece of clear packing tape and covered over the exposed holes on the bottom so that the adhesive in the hole on the reflector tape would not fill with dirt. Simple and quick to put together for just a few dollars.
Here is how they are used. Find a level spot on the site with your Roadtrek. Take one plate and it it along the side of the rear tire (driver's side of the van), right at the edge of the tire. Put a second plate at the very back edge of the tire so that you know how far back to back in. (If you are in a pull in space, do this instead on the front edge of the front tire.) Next, take a third plate and put it along the side edge of the front tire.
Now, when you leave the space and later return you just have to look for the plates on the ground and pull in along side them stopping when the tire reaches the cross plate (rear or front). If these plates on are on the driver's side you can see them in the side mirror as you back in during the daylight or if illuminated with a flashlight by your partner outside directing you into the space at night.
This really does work - on concrete, gravel, grass, or dirt sites and these are small enough that they will not be noticed by anyone but you - and who would want to steal this. Of course, someone who is not nice could come and move them, but you will know right away if you level(s) are off when you pull in. It makes for quick positioning every time you come back to your space. If you are in a space that is just not level and need to use the Lego-type leveling blocks, just mark the location of the blocks with the same plates and you will not have to leave your blocks behind - as these do get stolen. And add a note on your departure checklist to collect your plates and put them away before you leave for the last time.
Over time of using these, there have been several times when we have returned to the campsite and found these missing. I have made a larger and more obvious version using a block of wood with a red oval reflector on top and these on the front edge - in addition to what I have shown in the photos above. And sadly, because it seems that children in the campground find these attractive to take, each has been labeled - "Do NOT touch! Do NOT Move! Do NOT STEAL!" We have been using these now for several years and they do work in getting us back to the spot on the site that we have found to be level - and marked with these - without starting from scratch each time.