I've recently painted my 280 with a single stage paint over epoxy primer and since it was my first real paint job, got some orange peel. I've sanded it all down (no more orange peel) sanded with 600, then 1000, then 1500 and 2000, buffed with Mother's heavy cut with a variable speed rotary and up close still see fine sanding scratches, I'm kinda at a loss as to what to do any help will be appreciated.

Some single stage enamel can be soft when compared to urethane . Change your pad and switch to a less aggressive compound . McGuires #2 as an example. If your referring to a long type of scratch that looks like a missed primer scratch, you will need to lightly and carefully resand that area and repolish hoping you dont go through the top coat. This type of scratch is usually caused from a small piece of dirt getting in between the polishing paper and the topcoat. You can hear it when sanding if there is one stuck in between. Rinse often to minimize this problem.