I just used front fixed belts in my Anglia estate when my lad was brought home from the hospital. Fortunately they were long enough to go round the baby cradle thing. I made my missus get in the back too just after her caesarian too!!! what fun……
They only time they not allowed in the front is where you have an airbag.
I already have the belts fitted and as there is an initial forward movement in the event of a collision before the belt locks. this is the bit that is of concern me, would the seat move with a tipping action?
Well its no different to the adult going forward slightly, in the event of an accident, it all happens in a split second, once the belt tightens, nothing can go anywhere. If you are that concerned, bolt in, using the same mounts a fixed lap belt to hold the seat down, leaving the inertia in as well to do its job. 2 belts on same mounts effectively.
Done a couple of runs now. Baby seat fits in the front(rear facing) ok with the inertia reel belts that are fitted. Dont know what they are out of as they came with scruffy(thats the car not the Granddaughter).