You can strap yourself just as tight by:
-first, pul the diagonal part up till the horizontal belt part is as tight as you want
-2nd, push yourself against the seatrest rolling up the slack in the diagonal belt
-3rd do a quick pull down on the diagonal belt so it locks
Belt will stay locked and hold you tight
I do this on trackdays and it works perfectly, no need for some kind of clip
With stock seat belts I would not be concerned. You're concerned they'd be too-tight in an accident then they're already locked by the described device or procedure (instead of locking during an accident). Remember, however, that many newer cars have seat-belt tensioners that dynamically tighten the belts on impact. If they're doing that given all the research they do, I wouldn't be concerned about this.My question is - does this interfere and/or lose safety of the stock seatblet. What I mean is, in my understanding, the stock seatbelt is made so that if you have a front collision, your body turns around the belt and mitigates your head going forward and snapping/limitign damage.
With it so tight, it would seem to me that such benefit goes away and you increaes the chance of injury - or worse - paralysis in case of an accident.
This is one of the risks with harness belts (w/o a hans device) from what I've heard and the suggestion away from using them on the street. It would take quite an impact, but I'd hate to know that just b/c I put myself in a 4 point harness, I snapped my neck whereas in a stock seat belt.. I'd be hurt but at least not paralyzed.
Interested in hearing some thoughts..