Re: Someone has keyed entire side of car!
You may not need a bodyshop job if especially if the scratch hasn't gone through the clearcoat. If it's just the the clearcoat by a clear touchup stick, touch in the scratch to just proud of the surface, rub down using 2000 grit and sanding block, buff with rubbing compound, colour restorer then Autoglym Super Resin. For best buffing results you'll need an electric polisher. If the scratch has damaged the colour coat then use a little colour first. I suspect Metallic paint will be more difficult than solid and dark colours are better. I've done this on Alfa Red and you couldn't see the scratch unless you looked closely.