I think if this is your first model your best bet is to go to a shop like Halfords, get some aersol cans of the colours you want and some primer and try to get a good finish on the body of the car as it is and feel satisfied that you completed your first kit.
If you're really determined that you need these parts then you'll need a model shop. I noticed you're from Cork so your best chance will be Marks Models on Oliver Plunkett Street in Cork City. It's not the biggest model shop in the world but they will have a small selection of kits, paints, glues and puttys.
To make these parts you'll need some putty, some sand paper and a lot of patience and it can be easy to get discouraged. I know, my number of kits started greatly outnumbers my number of kits finished. But if you stay at it you'll be rewarded by the feeling of having accomplished something.
Put up some pictures in a Work in Progress Thread as you build and you can get advice from the members here. Some of the best builders in the world use this forum. Hope i've been of some help and look forward to seeing your progress.