Remember I am an amature but I have painted several cars and did minor repairs on scratches and dents. I would use 3M 3000 grit buffing compound (any brand is fine) buff off the over spray. then find a good spot to mask off the rear end where the scratches are and degrease, lightly sand with 1200-1500 grit sand paper and reshoot a couple of coats of clear. Then rebuff to blend back in. Buff after about a week, because the clear will be good and hard so it will buff evenly first with the 3000 and then with a finish coumpound and wax. I you buff to soon the soft clear will buff easier the the original paint and have a slightly different look to it. This is if the scratches are not in the paint and just the clear.