Guys, here is the problem,
I have very little knowledge of paint and im trying to spray paint a car part.

I know it will probably work better or cheaper by taking the part somewhere to get it professionally painted, but I want to do this on my own. I am somewhat of an artist..so I like painting stuff. Its a pride thing.

I am spray painting a stock spoiler of a 1992 Eagle Talon TSI BLACK

1st and only Attempt so far:
Parts
1. Krylon Plastic (no sanding, no primer required) spray paint.
2. 300 grit sandpaper
3. Sanding block

I sanded it down really well (couple of hours) and then applied multiple thin coats of this Krylon spray paint and let time to dry and all that. It didnt look that great as it had a flat black appearance to it....., so when I go to put it on the car...I get a small scratch from a fingernail. I was like FU*K...all that work and paint that didn't even last for ten minutes.

Then I asked a buddy who is a professional painter....mainly known on IA for painting high quality rims and engine covers. He said the best spray paint option is to use Duplicolor Truck, Van and SUV paint, then clear coat it and then sand with high (like 1000) grit paper. Another friend suggested using good finishing compound after the painting is done. I really just want a decent lasting, glossy black finish...but there are so many spray paints out there..I dont want to waste a sh1t load of money.

Can someone please guide me....REPS and appreciation will definitely be added.. Thanks