4A Brenda's more swanky upmarket transport? (7) ?o???h?
6D Party independent leader has no back passage (7) ??c?i??
(I'm thinking FACTION, but how does it parse?)...
9A Force instrument on Trump's powerless sidekick (8)
Last letter E.
And
12A White wine in extremity and a snack (7)
Last letter E
This will help open up the top right-hand corner. Thanks....