This could be done with a jacket, but better to have overalls with a webbing harness integral with the garment.
A 5-point harness, without the visible harness; always correctly adjusted because the adjustment is in the garment, not on the vehicle.
Spring loaded ripcord style release handle mounted on left upper chest/shoulder releases all catches simultaneously in an emergency by tensioning steel cables..
Normal release via a pushbutton on the console, electrically operated.
On impact, distributes decelerative forces over the entire frontal area of the torso, and doesn't shock-load the collarbone like over-the- shoulder harnesses can.-- 8th of 7, Feb 13 2014 very vaguely related... Bicycle_20Seat_20Shorts [normzone, Feb 13 2014] The fashionistas are going to have a fun time with this one - I can see the swimsuit model of it now, consisting of only the mechanisms in water and sun resistant materials. (+)-- normzone, Feb 13 2014 So, is the idea that you put this overall on, then get into the car and clip it into attachment points therein?-- MaxwellBuchanan, Feb 13 2014 Kinda, sorta baked for pilots in pressure suits.-- DIYMatt, Feb 13 2014 random, halfbakery