Mate, the car isnt that far off from been finished, is it ?
From what I see, you got it on its wheels, engine and gearbox? in, all nice and painted, bodykit on, brakes done?, roll cage in, exhaust done.....
To be honest I cant think of anything else that might need to be done that takes a lot of time !
I mean, you could probably finish it within a day !
Mate, I know its frustrating and its probably the last thing you would want to hear right now, but if I was in your shoes, I would pass on the current championship and focus at a different one that starts later perhaps.
You know, start off with something from the beginning.
If you missed 4 races already and about to become 5?, then whats the point of punishing a freshly built car with the odds of winning the championship diminishing ?
If other races arent an option either or if they are in the same status as this one (already started), it hurts me to say that I would just finish the car, hit a few track days to test it and fine adjust it, put it aside and be ready for next year before everyone else and finely tuned.
Again, as the other guys have offered, if there's anything we can do to help, please let us know.