Wheel arch trim fitting

I'm planning on fitting the GTi wheel arch trims to our Golf. However, I'd like to order whatever fixings I need at the same time as the arches.
So, can you tell me please, how they attach to the arch and what fixings I need?
Thank you

 

We put a set on the green one Phil, pop rivets with a black head on the arch lip.
The arches did need trimming a little to suit, and the front tail to door trim had a very dodgy clip which needed a hole drilled on the replacement wings.
Reasonably simple to fit, may be an idea to use self tapping screws so you can remove to clean the grime that gets trapped behind them and try to alleviate rust acceleration.
Have seen arches on a mk3 stuck on with silacryl or similar, but all it appears to do is trap water and hold it there, causing problems like Allie's car had with glued on trim....

 

Thanks Dave, self tappers is a sensible option. Is there a some sort of push clip at the bottom too that i need a grommet for, like this? Or is this for a different purpose?
https://www.heritagepartscentre.com/uk/357853586d-grommet.html

 

This gives you details of the original fixings for a 1990....https://volkswagen.7zap.com/en/rdw/golf/go/1990-110/8/853-170020/

 

Very helpful, thank you.

 

Think, as it was a year ago I did Allie's car, the normal trim holes are used plus the pop rivets,
Think with the mix of pattern wings and pattern arches there were discrepancy between holes lining up to be honest, and a tweak for lining up on front door to wing trim level.
I'll try and get some photos of the white golf as that came with arches as it's a driver.
I've seen two types of arch kits, discounting the wide grp ones, some have the tail on the front arch to match the door trim, and others are just round arch, no return bit. Rears all seem to have the small bump to line up with rubbing strips.
Really need someone to start making G60 replica arches in fibreglass, surely they would be popular.


Edit, the rears used some of the original trim holes with those 'cups' as on door trim clips, pretty sure I just filled silicone into the unused ones to seal up the hole.

 

The white one has wide head pop rivets, and we screwed the ones onto the green one.
Still have rivets in package in garage.
Did have to put a screw in the rear arch at sill level to pull it in, may be as it had work in that area and so a little different shape?

 

You may want to paint sills black, or use the textured stickers available so they tie together nicely too.

 

Thank you, very helpful. I think I'll order the arches and then decide what fixings will work best depending on how well they fit and whether they need holding more securely in certain places. I will be attending to some small patches of rust as I go........ watch this space.......