I have just done a run with this and player guidance was the only problem I had. The ramp on the intersection does not stand out and the intersection that was mentioned before still has problems. I have used InfoTextBoxes to guide the player in new level Icecoat. Maybe that will work?

I have a few issues with this map so far.
1. When you come to the intersection after driving straight for awhile you have the yellow caution marker, needless to say I drove right through it and right into a wall. I think you should put an arrow there to point us in the right direction because not everybody even understands the yellow caution things.

2. The tunnel may need a cooldown as it cuts real close to exploding.

3. After the tunnel you have a transfer and I think it is up to high cause I was unable to make the transfer, and you are already about to overheat so you can't just fly.