Well it was 2 o'clock in the morning here when you posted that last one, so don't expect a rush of replies too quickly.
Clear enamel is what I sprayed the Skyline with, but I wouldn't recommend it and will probably not be using it alone anymore. Pure enamel is very soft, even after curing for days, and is not meant to be handled. I ended up with indentions all in the finish of that car by carrying it for a day in a foam cushioned case.
I believe you can add hardner to enamel to make it more durable. You can also use acrylic clear which is very hard (durable) and dries fast, but I've heard someone say don't use acrylic, so I'm going to do some more research.
The tricky part about clear coating is getting the right amount on the car. It's hard to do from a spray can, because they spray so much. I used an airbrush and it still took me about 3 cars before I got the coverage just right. Too little and you end up with "Orange Peel". (finish is rough and wrinkled...looks like the surface of an orange) Too much and you get runs and too much thickness in dips and cracks, which doesn't look normal.