So I was getting bored of the same old test at the stunt park. And I wonder if expanding it would be possible on the way I show it could be done. Starting by doing some modification to the stunt race, by simply moving it further and thus allowing more room for the tests. This is what it would look like in theory.
Now for the road connecting the exit of Row 4 to the stunt park would be shortened due to the fact the race tracks are pushed off the side of the exit of the Row.
Now for the actual area that would be needed for the expansion could be done by moving the tracks like before to give more space for the test. As well as moving up the bowl stunt thing to allow a bigger area to be exploited as well.
Green Arrow means where it should go
Red is for where the tracks will be
Yellow is for the area of the expansion of the tests