Seat fixing bolts

Hi,
Does anyone else on here have problems refitting the 2 fixing bolts that secure the seat to the frame - or is it just me?
I can never seem to line up the treads on the 2 allen bolts with the threads on the sliding bolts beneath the seat.
My problem is that the nuts under the seat move about and are hard to locate,especially as I cannot see under the seat, once it is in position.
Does anyone have any tips?

Thanks.

The captive nuts under the seat should be captive and tight. They should not just slide around once you take off the seat. If they slide loosely , you need to replace them. Also , try to mark where they go when its bolts in so you can replicate the position. Tony .

You can remove the nutplates and tighten them up with pliers, use an awl to align the nutplates with the holes in the frame, insert the capscrews and tighten them after both are in and threaded up.

Is there any danger of the seat fixing bolts coming loose due to vibration, and falling out. Should one put a lock washer on the bolt before tightening?