I find it easier to mask and paint than to struggle with all the paint scraping and fixing the destroyed paint afterwards.
Paint tool, scrape paint, glue or superglue, check result, exhaust vocabulary of profanities, repair the paint job and get clean demarcation lines between tool and vehicle.
OR
Glue tool to vehicle, paint vehicle, paint tool with clean demarcation lines.
What I wound up doing is sticking a fractional toothpick into the hole in the vehicle to plug the mounting hole and prevent paint from getting into the hole, so the joint when I mounted the tools would be plastic-to-plastic. I had my modelmaking interrupted before PE became popular – something that I’ll be remedying now that I’ve got the time to redevelop my skills – so I never had to deal with attaching folded PE to the side of the vehicle.
The only time I paint is when it is nessary. Like if there is a full interior where it will be seen. Other wise I tend to wait until I’m done building.