I have worked with similar technology solutions; these are on the more primitive end of operations. It appears that the key data point is pin 5, you will get a 1 if a vehicle is probably parked there and a 0 if it is not probably parked there. Based on the number of factory test notes and the unknown component weight, there is a chance that you will be beta-testing this thing, except you won't receive any support when you do point out errors. It looks like you might be able to calibrate a base reading used to calculate if a vehicle is present and how long it has been there, but the details are very poorly written.
This is probably a total waste of money, there is no way it is worth 8 dollars. You are still responsible for transmitting the data it gathers to a base station and providing energy for the sensor and transmitter. You will need to design some sort of protective enclosure that is water-resistant. To avoid theft or vandalism, you may have to dig into the pavement and partially cover up the sensor in cement so it is impossible to remove from the site, but have fun when the device needs batteries again in a few years.
Looking at related items, several sellers appear to be selling a similar item. If you put all the data together, you might have a functional specification. One thing in common is that all the vendors have one sale at most on these items.
tl;dr: You can do better for cheaper.