Just some small things: only personal taste and no criticism.
-The dittering on the grass could be a bit different to make it look like its mowed lawn. Now it looks a bit messy and clustered.
-Maybe you could have tried to recreate the stand on the inside of the last corner that looks like a Butterfly.
Maybe by using gates or as an Lmap Object. It´s a unique landmark of the track and I kind of miss it.
-The Lmap cars in the lower right corner are a bit too big in comparison to the track.
-You might have added some more Lmap details, just to give it a special touch...
BTW some walls could be better too (e.g. inside turn 5).