Land Nav in the Army was my biggest help, but it was still weird doing it on a computer in that stressful situation, so I took advantage of the unlimited practice. I think I went through it 5 times (at least). I did several different things to just help with speed. The first thing I tried was I took scratch paper and drew out the directions (N at top). Then I'd hit the practice and put my pencil on the paper in the direction of travel. Then I would spin the paper to have the pencil face the computer (as if it would be the image of the parking lots on the screen). I used that just to get myself more acclimated to what the test was asking. Since the process would've added time to my process, I'd still use that during the other practice exams, but after turning the paper, try to memorize which directions were to my left and right, front and back. So if headed SE, I'd know that S and E are to the front, N and W to the rear. Then N and E are to my left, and S and W to my right. Took the practice a few more times just to make sure I had and off I went. Missed 2 or 3 and had pretty fast reactions after.
Until your test, I'd say make some flash cards. One side have the map and the direction of travel and the parking lost, he other side having the correct answer. The pencil trick can be done that way to prep before even getting to the test.
Hope that helps! Good luck!