That Camaro looks great. Very well done. I've seen some people end up with what I call tiger stripes. The even flow on your car is fantastic. I actually loved the look of my car in the silver base. As for the question of masking, we use a foam tape, round and about the diameter of a penny. The round shape allows a soft blend, If you watch the video you might see the tape in the door jambs at the quarters, with the doors out slightly. This gives an even blend with no need to sand after.