It's not an issue with the car, you just need more experience. The Focus is an excellent autocrosser, which even in stock tune should be enough to lay down some very impressive times. Also, the mods you have aren't very applicable for AutoX either. Get some very good tires (Azenis) and some experience. You'll be shocked at just how fast you can be.
One of my first times out I was destroyed by a guy in a basically stock '70-something diesel Rabbit. With a massive 78BHP (new) and race tires, he was putting Mustang GTs and many other "faster" cars down for the count.
Driver = 80%
Car = 20%
You really wouldn't be much faster in a 240SX either until you get some training.
None of this is in any way a knock on you man, but I have to say that I wasn't stoked on the Focus for a while either. But I stuck with it, got some training (lots of events and an Evolution Autocross School), and now with my daily-driver street tires I am usually near the top of the pack in raw times.
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...