Paint on these isn't soft. That stuff is freakin rock hard compared to some others. the 335i ghosted that you have is probably a bit of adhesive left, and you might washed it off or something.
Nope - Goo Gone, clayed, cleaner wax, polish the sealent - no residue for certain. Car was not even washed during that approx week and a half period during which the color changed - it was only driven 3 times on sunny days and sat in the garage the rest of that time. At least in the end the color evened out and the color mismatch evened out.
By the way, I also had slight impressions in clear coat where th Welt had applied small foam bumpers to my Euro plate during ed - and no it was not rub in or a mark cause by debris and vibration it was pressed into the clear - it did buff out.