I have ski completely torn down, many upgrades this year. I'm wanting to paint engine bay. I've already painted outside of ski and I have experience using automotive paint. Can anyone give advice on how to prep surface and what color to avoid? I used epoxy primer on exterior and used 320 grit to make sure primer adhered. DuPont makes 222S adhesion promoter, so I was wondering if anyone has taken a different route with good results?