A small scratch on a new car, yep a real pain in the rear to say the least. The first thing to determine is the depth of the scratch. It may be short in length and visibly look small or minor but if the depth of the scratch has reached the base metal at any part, mainly the middle of the scratch, then none of the car products will remove the scratch.
So the obvious next question is, "how do you determine this?" and I'm afraid without mad expensive equipment in the region of scanners and X-ray this is virtually impossible.
So what can you do? The best first approach is to use a very small amount of products like T-Cut, Cutting Compound or Paint Restorer. Use soft clean cloth and apply an amount of product about the size of a contact lense. Rub very lightly in circular motion and wait a few moments for product to dry. Then remove product with another soft clean cloth. Finally apply a light coat of car wax, any type will do, in exactly the same way as the paint restorer product. Let this dry and remove.
If the scratch has gone, good show, but monitor the area were the scratch was and if you see any bubbling, blistering or discolouration visit your local paint shop.
As I said earlier if the scratch depth has reached the base metal then some form of repainting will be required.
Don't accept the advice of the paint shop straight away, as they will probably advise to have a least the whole panel resprayed. There are many companies now who specialise in removing, stone chips and minor scratches with the use of very small portable air compressors and tiny spray guns.
I have used these types of companies before and the results they achieve are excellent.
Failing that, simply send me a ticket and I'll come over and sort for you. I'm overdue a holiday,