i would suggest keeping copied background, for this stage
i know when i brushed my first one, i wasnt really satisfied with it tbh, but got some nice motivational comments so decided to finish it
so, redo the bg->either real pic or brushed one...
redo the body, try to lay an orange paintlayer over the original car, and this way you can see the color etc differencies lots better, keeping the paint much more sensible in that way
failing that, use some reference