I did notice that you didn’t primer the roof on the mini or the spare panel, any reason for that ? Also when you say you have polished it have you machine polished it because machine polishing will get a lot of the orange peel out
You don’t need to primer if you’re just painting over the top of existing paintwork. Primer if you’ve done filler work to help smooth out any imperfections. Also useful if you’re changing from a dark colour to light.