Same problems here too; I trimmed and lowered the fluid filler under the moveable grille, removed some of the underhood structure and moved the spare tire slightly back. For the rear, it was much more challenging- reshaping the area where it meets the roof , grinding that area to make it thinner so the cover will fit flush and reshaping the sides to make it flush with the center section area was done, still not perfect , but better [see attached] I applaud you having the paint skills to sand and clear coat your bodywork; I did use a paint sanding/polishing kit to remove most of the orange peel, but not all of it. It is a shame the body fit and paint quality is poor for such an expensive model to build, I wanted much better.