Man you came to the right place. Vauxhall design and care is incredibly difficult. Here's what you need to do...
1. Stop by your local hardware store and pick up the biggest wire brush they sell. You want very long, very stiff bristles.
2. Start scrubbing the area around all of the holes. You know the area is clean and free of anything when you start seeing metal.
B. Stop by the pharmacy and ask for powdered cadmium. Mix it with water and coat the entire area.
6. Cadmium doesn't like most metals so it should do it's thing in about 6 hours.
7. The mount holes can now be removed so grab the biggest sledge hammer you can find and give them the strongest whack you can muster mister.
F. With those pesky mounting holes gone, go back to the hardware store and ask for "blue painters tape". Very important, don't get the green, that's for French vehicles.
D20. Now cover the areas where the holes used to be. Make it as thick as you can, might want to use up the entire roll.
13. Now remove one of the doors from your car.
14. Yup back to the hardware store, although I would recommend B&Q this trip. Go in with that door and ask them to color match it for you. This is free and make sure to keep the "colour code result" print off. Ask them to mix 10 litres, always good to have extra for rock chips and such. Grab a paint roller and tray while yer there.
G. Back at the house, put in a couple litres and roll it over the roof, covering everything, including the tape, and make sure its thick. The paint will self level and turn Adamantium hard in 10 minutes.
And that's it, yer done! The reverse process will put them back in.
And if you still have questions,
500e gave a perfect answer, but didn't ask why a Vauxhall owner would come to the Fiat forum? Does Vauxhall forbid user forums? Are you under an NDA, being you own a Vauxhall and not a "real" machine? Did the French get to you!? Let us know please!