To make cevelopment more interesting, why don't IGP introduce testing. It can be done on any day at any one of the 17 circuits on the calender and the data could be used to help in future races as well as to develop the car.
It would cost money and require a third exclusive test car but theres always a pay off. You could imploy a test/reserve driver which would allow your team to develop competent drivers to race for the team in future.
Any Thoughts?