Our cars in race trim are about 2600lbs loaded. That was with a spare and gear, underbody protection, etc. Probably without that, it would be well below 2500lbs. Keep in mind, this is a caged car. The rear doors weight next to nothing once they are gutted. With lexan windows, they weight less than 20lbs. Carbon may save another 3-4lbs. Same with the hatch. Most of the weight savings on those parts come from replacing the glass with the lexan. On the RS we are building, we would save less than 30 pounds by switching the rear doors and hatch to carbon for the price of $3800. We have minimum weight for the Focus and have to run ballast anyways. On the Fiestas, we don't, so can do more. I would wager you can get down to 2300lbs without a cage and super aggressive weight reduction.