[NOT A TA]

I've seen some "trap door" under floor setups that hide everything and keep all fluids outside the passenger compartment.

If you're going to track the car you will be replacing all the brake fluid before each outing unless you go frequently. So if you go 2-3 times a year you'll probably change all of the fluid 2-3 times a year. The brake fluid absorbs water over time even though the systems sealed which lowers the boiling point of the fluid. You do not want that to happen on track!