Another new member here looking for help. This wont be the first car I've painted. However this will be the first nice car, and first using metallics, the others were SS, solid colors, beaters and cars I got for cheap and flipped (mechanic by trade). I have done a good amount of reading on this site and others I've come across.
I have read, the best all out thing to do is go down to the metal, epoxy, prime, bc, cc. How often is that the case, or is that really done? I've also read about just sanding down the clear and painting over paint. That is what I have done to all the cars I've painted.
Anyways the current car I want to paint, I want to do a really good job on. However the surface I am starting with, is bad in spots, and I dont know how to go about tackling it.
For starters this is my trunk.

The lid looked like the spoiler, however I sanded it down smooth and just used some rattle can clear on it as a temp fix. With hopes to keep it from all falling of and maybe starting to rust. It looked all black for a few weeks then turned like it is in the picture. Before I messed with it, it just started as a little spot and grew over time bigger and bigger.
Next issue, roof and hood. I think the sun and maybe someone over buffing the car has taken the clear off, or pretty far down. The just dont look glossy or wet anymore.

closer shot

They both just look dull, you can buff and wax them really good, and it will kind of hide it for a few days, but then it just comes back. In the 2nd & 3rd pic, if you look at the top of the pic you can sort of see its just a white haze. Is that just shot clear?
The rest of the car is really glossy still, maybe just the sun ate up the top side of the car?
Ok so now, where do I go from here?
How do I ensure a good bond?
How far down should I go?
Since the sides are in great shape do they need the same treatment as the top of the car?
It's kind of a loaded question I dont even really know how to ask well
