I thought they were captive nuts behind there. Has the car had any bodywork done in the past?
You should still be able to take off the trim panel on the inside to remove the lost nuts and refit them.

 

My thoughts too. The seat belt reel most likely shares a cavity with the striker backing plate.

 

Try a strong magnet and slide it up so you can see it then secure whilst replacing screws🤔👍

 

Thanks so much for replying Andrew, Brendan and Scenic. Much appreciated.

The reason I removed it was because there was some kind of gunk on the back of the plate which made me wonder if it had been messed with previous to me owning it. So there was simply a metal plate behind the gap shown in the pics. This plate was behind the bodywork and then the face of the door striker screwed through to that back plate. It's that metal plate that's fallen inside. It felt a bit of a bodge to be honest. Removing a dodgy door striker plate shouldn't mean the lock falls apart so you can't locate or lock the car! Bit of a design flaw if normal!!

On the car (from out to in) it's: Door Striker | Car Bodywork | Metal plate with screw holes. <-- this is what's vanished into Scenic outer space...

I've removed the rear trim, the trim by the door but can't access into where the plate has fallen.
Where the rear seatbelt goes down into the bodywork is just the other side of where the back plate has fallen, so you'd have to access through and then across. You can get a bit more access from the boot if I pull out the carpet a bit - but wasn't enough to get through!

I will try again with a large magnet or get the Halfords magnetic pick up tool to see if it helps! This would be amazing if it worked but hasn't yet.

 

When you unscrew the door striker plate nothing should fall down, defiantly captive nuts of sorts, just checked mine. Mine is a Clio but they should all be the same. You will have to remove the inner trim panels, possibly the ones in the boot area so you can reassemble the striker. As its already been bodged you will have to put two correct size nuts and washers behind. You will need the access to get a socket or spanner on the nuts whilst you tighten the striker plate screws.
A bit time consuming but it needs to be secured properly.

 

Forgot to say.........you are not the dim witted one, its the previous person who carried out the bodged job.

 

Ha! Thank you! Actually a relief to hear that. I believe the front plate was on with some kind of paper/glue substance and the piece of metal at the back was also semi glued on. It certainly wasn't captive to anything so I do suspect a previous bodge! I will attempt another removal tomorrow although working from a 2004 online Scenic manual as they don't seem to provide one for the version of car I have. Think part of the boot shelf will have to be removed too.

Again, thank you and unlike many who say they will but don't, I will reply with what happened and who did what to get this resolved in case it ever helps someone else!

 

I'll be honest I have never worked on a Scenic but if you have a manual for a 2004 I would think trim removal would be the same, although some pieces may be a different shape.
Good luck with the job.

 

So it's been to a local garage after I was unable to access the back plate. They are a slightly smaller garage and are unable to access the plate either, perhaps don't quite have the right kit etc. So it looks like it will have to be booked into Renault! Will report back!

 

OK just to update anyone who this may ever help. The Renault garage (very helpful) were also unable to gain access to the part which has falling down inside the chassis. They also confirmed that the backplate under the bodywork was a dodge job by someone as the backplate shouldn't fall inside the car but should be welded on. So it's off to a Renault approved bodywork specialist to cut out, replace with the correct part, re-weld and re-paint. All because at some point someone hadn't put the original back plate on / back on properly, unknown to me. In the process the car has also had to have a new battery and have a 'fuel injection service' issue dealt with. Feel like getting another car!! Thanks again to everyone.

 

Goodness knows how on earth they managed to bodge that up. Get ready for a slightly largish bill!

 

Ha yes, already a couple hundred down... 😟