i suggest setting the downforce front and rear quite high and lower the ride height to near minimum also run on superhard tyres and pit every 10 - 15 laps , you'll destroy the field but only noticable when they make there 1st pitt .
the time trials are quite similar to some of the easier license tests , there is only one real challenge in time trials , the almighty COMPLEX STRINGS takes a really good class of driver to complete this course esspecially if your looking for 1st place
If you are doing the Roadster Enduro you cannot change the settings on the Miata, everything has to be stock only oil change and tire change are allowed.