i would not do lacquer thinner unless other things fail to do the job. it can seriously fade the trim. try tarminator with a plastic blade. or even a light solvent. it might take some elbow grease but its better then ruining your plastic trim.
this was about 3 years ago when i made a big mistake once and i used thinner to try and remove bird poop etching on a trim. with just a little dab of thinner the texture was stained and faded. please do not use thinner.