Hmm, well if you're only looking for a one step, I would use Auto Finesse Tripple. It's labeled as an AIO, but I think it does quite a good job removing minor defects. It leaves the surface ready for an application of Tough Coat (their sealant) or wax of your choice.
I've always liked using Tripple and following up with Tough Coat. It does great things.
'11 BMW E92 ///M3 - ZCP and DCT
'15 Ford F-250 - Lariat, 6.7 Powerstroke Turbo-diesel