Meth Failsafe Setup

So I was PMing with Ghiz the Whiz and discussing what my setup was going to be.
I figure I should post it up here to see what peoples thoughts are.

Car starts
-Pump is on, auto off when hits desired pressure
-Pressure sensor grounds the idle switch (Ghiz's suggestion, which I like!) telling it to use the high octane fuel map
-Punch the gas pedal, at set psi the solenoid that is right before the nozzle opens and sprays the meth

My thoughts here are if there is ever a time that I run out or the line bursts or something like that than the switch won't activate and I will stay with retarded timing and the car will be fine.

I've had my meth line pop off before (old worn line). I replaced it with a new line since, but it felt like it was raining inside the car before, and that was with it injecting at a certain PSI. Had the pump of been running constantly, then it would have soaked me with methanol.

Yeah that's the other part is I haven't figured out where I will be mounting the pump and resevoir.