I cannot for the life of me remember what grit came with the 3M package..
With those condition its in, me personally, I would start wet sanding 1000 (maybe even 800), 2500, 3000.
after 3000 grit I would hit it with Megs 105 then Megs 205 and finish off with Megs PlastX
that's just my 2 cents...