GS...well done!
We have found each "tech" even at the same tracks will interpret the rules a little differently.
They have approved our "down bar" consistantly and is made to be removed or added in minutes. It fits in the car so nice without interfence to the driver or passanger we have found that the owners install them an just leave them in. The diagonal behind the driver is NOT needed, unless you start running some very serious times.
If we pop into the 9"s this season, and we fully expect too, then we will have to add a "halo" and side bars. Now that will be a little tricky and still keep it street useable!
DV
PS..the owner of this DV II is rather tall, thusly so is the main hoop to meet the 2" inches higher than the helmet rule!