If it's composite then maybe a colored t-cut is the way to go ?
I had an issue on a caravan an (ex)employee decided to spray neat tfr on it before cleaning - we were left with big x-marks and runs
I tried various things - steam, cleaners, rubbing - nothing would bring the light stain marks out - until we hand buffed with pink stuff - this lightened and brightened the whole van - so blending in the tfr marks
Darran