I have the Brey Krause mount in front of my passenger seat and I can reach it if I unbuckle my shoulder straps. As DJ says, this mount does limit forward seat travel, and as a note, this makes this mount not compatable with the hardbar lap belt mounts which attach to the two rear seat posts (at least on my car I can't get both to fit).
As a lower cost alternative to the Halon 1211 or 1301, I use a 2 1/2 lb Amerex siliconized Sodium Bicarbonate extinguisher which IO Port also sells.
I actually had the opportunity to use this on an engine oil fire in late 02 as I was moving from Seattle to Memphis. Driving down the freeway I drove past a stopped economy car with a well developed fire in the engine comparment. Hood was open and 1-2 ft flames visible. I was in the Z06 and did a 60-0 braking exercise, which freaked out my wife who was dozing. She was even more disturbed when I grabbed the extinguisher and jumped out. :eek2:
Couple bursts on his engine and the fire was out. I shot a couple more bursts to cool it down, then waited with him for the fire department to show up.
Turns out he was driving with a known oil leak onto his exhaust manifold. Bad plan.