My first and so far only effort.  Straightforward but demanding track based mainly on Voodoo Island track and scenery. Checkpoint models I've borrowed from somewhere but can't remember where so apologies to their owner. Two shortcuts with one well hidden plus another shotcut leap.  The cars can come to grief in lots of places, but I've taken care to see that they don't all pile up repeadedly in one place - this happens in a lot of tracks I've downloaded.
Some stuff for those who like off-track wandering including two signposted "scenic routes" and a maze full of appropriate quotations carved in stone. Solving the maze is not difficult but finding where it is and then driving into it will need some headscratching and fancy driving. 
My record (8 car professional) is 3 min 16 secs.
If you find any wrinkles or think of any improvements contact me at donshamrock@hotmail.com
Good luck!