Paint and body guys

You're talking about overspray correct? Or are you talking about rubbing/polishing compounds?

Is this urethane enamel paint? If so, once the paint has cured, you can use denatured alcohol and wipe it off. If that doesn't work you can use lacquer thinner (again this is risky as some urethane enamels are of lower quality and do not have very good solvent resistance)
Do NOT use acetone...
If not coming off then you will have to sand off with 1000 or 1500 grit, then cut with 2000 grit and then use a buffer with rubbing compound, then go to polishing compound. I had to do this with my motorcycle tank once, it had clear coat runs on one side. sanded out the runs with an 800 grit sanding stone. Then used 1500 grit stone then sanded the area with 2000 grit to blend. then did the rubbing/polishing compound as mentioned above. Came out like glass... Then realized the area I did looked better than the rest... So I did the rest.
DO NOT wax for at least 45 days after painting, (again depends on the paint/clear coat) I waited over 60 days to be safe.

Not sure if you knew most of the other stuff or not, if so apologies for ramblin' on.
My experience has all been motorcycles.
I'm going to be painting my duster soon. My first attempt with a car.