How Screwed?
 

Anyone able to tell me what part this is & if it's replaceable by chance? Also, how screwed am I exactly?
This is where the rear passenger trailing arm attaches to the body & the cavity where the screw resides.
Many, many thanks!
https://cimg6.ibsrv.net/gimg/www.civ...bcccc41794.jpg
https://cimg7.ibsrv.net/gimg/www.civ...fc1fe150d0.jpg

Re: How Screwed?
 

Looks like you have enough good metal around it to work with.

Worse case scenario you could find a solid example of your car at a scrap yard and cut out the peices you need, then weld them back into your ride.