That's a very good first effort. One thing, at least from my viewpoint of running real autocrosses, is that the pointer cones are on the wrong side of the cone. Should be on the outside pointing you to go on the other side of where they are. Kinda like ^< for going to the left side of the upright, and >^ to go right. If you're interested in course design, here is a link to the manual that most people use for the real thing.
I normally run the XF GTR because it handles the most like a real autox car on race rubber. Don't know if you consider that a real car or not. My fastest times in the other cars you mentioned are about what you ran.
Try that. It's a real course that we are really going to run next month. I find it really helps to model the courses first in LFS in order to get the right mix of speed and maneuver.