The window units on my antique TVR are held on using what look like Rawl plugs...

However...

The little plastic inserts (Rawl type plugs) have a countersunk top and the shaft splits in two when you insert a screw...

Are there specific screws and inserts that are designed for holding things into thin fibreglass/ali?

I have never seen anything quite like this before....anyone know what I am going on about? And more importantly..where to find any?

[Edited on 21/12/08 by tegwin]

I've seen quite a few cars with trim pins like that. They can be a bugger to get out in one piece. No idea where to get replacements from though.

Have a look Here they do all sorts of stuff like that.
Steve.

Like these, this company will usually give a few free samples

http://catalogue.jetpress.com/Industrial.aspx?intGroupID=12917

most production cars inner plastic wings are held on by such clips

If the clip has a coutersunk head it sounds more like a generic Japanese type clip. Have a look at the Jet-Press site linked earlier for Toyota clips.

Also Wurth have a good selection of clips.

Is it anything like any of these?

http://www.wurth.co.uk/catalogue/pdfs/UK-CD_03_6055.pdf
http://www.wurth.co.uk/catalogue/pdfs/UK-CD_03_6035.pdf

Another sourc might be Woolies the trim people. If they haven't got the exact thing they can often recomend an alternative.

http://www.woolies-trim.co.uk/c-4-fasteners.aspx