As title really. Just wondered if there is a simple way of doing this without making things worse (e.g. delicate use of thinners). A body shop in Newport managed to apply masking tape to my rear diffuser wonky so there's a thin but really noticeable line of green spray on the black trim.

If it's there **** up shouldn't they be fixing it? Perhaps you could spray over the overspray? Not sure how that would look to be honest, I'd be concerned that thinners might damage the plastic.

I knew someone would say that. Just thought someone might have a miracle quick fix - and I'm shy in the respect that I'd feel really pedantic if I went and asked for them to resolve it... but it's got to go back in to Capitol in Newport for a tonne of other stuff so I'll go see the body shop at the same time

Didn't realise I'd get censored, makes it look far worse than what I actually wrote! tehehe (can't use a giggley smiley coz my browser won't let me, DOH!). You shouldn't feel bar about going back, you've paid them to do a job with an expectation of decent workmanship; it's probably dead easy for them to rectify anyway. However, I take your point it's a lot easier to fix it yourself at home if there is a "miracle quick fix" but I'm afraid I'm not your man for that. Hopefully someone else can help you out.

I think clay bar can be used to remove overspray mate