I bought some of that T Cut yesterday, one was a black T Cut Scratch remover, applied that and took all the marks out straight away, but the was a noticeable colour difference, but i also bought some black T cut colour fast i think its called that restored the colour perfectly.
Wished i had a picture of how bad the scratches were, and what its like now, might use this a few more times round the car to bring back the paint work in small places.
Would actually recommend these products!