I'm looking at a fixed back bucket for my drivers seat, and am curious what other street guys have done with their belt setups. Harnesses are pretty hard to certify and get road legal here, so that's a no go.

A bit of reading seems to show threading the belt through the waist holes is the way to go, keeping it snug against you. Some then mount a belt extender to make life easier

My question is, would a belt extender being constantly clipped into the oem buckle mess with the pretensioner in any way? Being that it will still think it's connected, while I'm unbuckling on the second buckle
My thinking leans towards no, but hearing it clicking each time I buckle it left me curious.

 

the belt extender is just an addition of a secondary buckle, once it it attached you won't be using the first oem buckle, you'll be using the buckle that comes with the added extension.
the pre-tensioner will work as intended.