Those look like sandpaper scratches to me - or more likely since you say you sanded with #2500 they are dirt scratches. Once you pass #600, the need to keep your paper, hands and painted part absolutely perfectly clean is ultra critical (of course it's important whatever the grit). Even the tiniest particle of grit will wreak havoc if it gets between the paper and part. I put on clean clothes, work out of a perfectly clean 5 gallon bucket so I can constantly rinse my hands and sandpaper and keep a water hose at hand so I can constantly rinse my part. It is pretty messy, but just wet. If you don't get results just continuing to polish, and you think you have enough clear, re sand to remove the scratches. Hand polishing is a bit of a chore, but you should get every bit the same result as with a machine. I do bike parts with a little pneumatic grinder which I adapted to take a 4" polishing bonnet so I can either use a wool pad or foam. I bought it at Harbor Freight for $20 I think way back and it still is fine after a zillion hours and saves a ton of work, but persistence with hand buffing will do the same. If your clear is good you should be able to get finest show quality by hand. A little late in the game now, but I tend to avoid sanding corners and edges as much as possible. There is usually very little peel in these areas and I try to shoot so these areas are very wet. That way I can avoid sanding and polishing these areas so much and risk cutting into the color. You can definitely cut through even by hand, so have a care at corners and edges!
