Need help with skinning a Formula Ultimate

[Eagle Racer]

Hi everyone,
I have the main part of the skin does, but the DRS flap is causing some issues. First of all, no matter which way I orient the logos, it's always upside down. Also, when I try adding a layer mask after flattening, it doesn't show up at all. But if I don't add a layer mask, it's very shiney and shows up twice, once open, once closed. Any help with fixing either of these issues?

Thanks,
Peter J.