Seat runner rear fixing S4

[Mileso]

Just fitted new sound/heat proofing felt and carpet and, correctly, fitted new s/s runners over the carpet.
My query is how do you bolt the rear 'inner' points. No bobbin (none on other fixing points either so nut/bolt/washers employed), just a hole through floor for bolt/nut and washer but the body is sitting on the chassis so no access to put a nut in from u/s.

Not overly worried as seat keeps them down when in place, but would like it to be right.

Solutions/thoughts welcome - glass/glue a thin nut to topside - or is there some expander thing that may suit - large pop rivet?

[1owner69Elan]

I will check later today but if I recall correctly the rear inside seat runner bolt (or stud) goes through a hole in the frame.

As original on my car. Body never removed.

Was your frame replaced?

You may need to drill a hole from the top through the frame. Not an owner bodge. As done by the factory on my 1969 S4 Federal. But, I will recheck and post a photo.

BTW. Are you using non tip runners?

[2tmike]

Bolts through the chassis flange on mine

[Mileso]

Cheers both. Will consider drilling.
Yes it has had a new chassis in its life and mine are not anti tip so basic angle s/s.

[1owner69Elan]

Here is a picture of the rear inside runner studs through the frame.

I have thread protectors over the threads, as shown. Mainly to protect my head when under the car.