Save your money !!!
Unless its a really bad scratch (Freddy Kruger style) I would suggest you get a Turtle Wax Stick & Polish Kit... (From Halfords) and use that....
It does a top job; the stick fills the scratch with wax & the Polish / shine afterwards makes it impossible to see if done carefully....
Only downer is you need to top up each Month if washed regularly... but trust me it works brilliantly !!!
Cheers;
Russ